Summary :
May 25, 2018 Under Windows, this partition cannot be formatted. System partition The Boot partition is the partition where Windows is installed, it is also known as boot volume. It includes a Windows directory. Similarly with system partitions, under Windows, this partition cannot be formatted. The previously 285MB partition labeled Recovery partition was now 500MB wile the partition labeled System, Active, Primary partition was still at100MB. When I got home I then checked Disc Management in a Workstation that I had upgraded from a clean install of Win 7 Pro 64bit on a new HDD to Win 10 Pro 64bit v.1511 and then again to the WAU. An active partition is a partition on a hard drive set as the bootable partition that contains the operating system. Only one partition on each hard drive can be set as an active partition or bootable partition. For example, if you are using Microsoft Windows, the partition that contains Windows is the active partition.
Accidentally deleted system reserved partition or accidentally deleted EFI boot partition Windows 10? Windows can't boot after deleting system partition? Don't worry! Now, this post will show you 3 ways to recover deleted system partition or fix unbootable Windows. Try them and then you can use the PC properly.
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Windows Can't boot after Deleting System Partition
You would feel helpless and desperate when Windows can't boot if you mistakenly deleted system reserved partition or EFI boot partition.
Tip: Since there are 2 types of booting mode, namely Legacy BIOS + MBR and UEFI + GPT, we talk about this issue from 2 aspects.
What Is System Reserved Partition ( Legacy BIOS + MBR)
When installing Windows 7/8/10 on a clean disk which is initialized to MBR, the setup will create a system reserved partition at the beginning of the hard disk and mark it active.
This partition holds the Boot Configuration Database (BCD), Boot Manager (BOOTMGR), Windows Recovery Environment and reserves space for the startup files which may be required by BitLocker, among which BCD and BOOTMGR are vital parts to start Windows.
If the active system reserved partition is lost, Windows will be unbootable since no BOOTMGR and BCD are found. And you may receive error messages like BOOTMGR is missing or Operating System not found.
What Is EFI System Partition (UEFI + GPT)
When you install Windows on a clean disk that is initialized to GPT, Setup will create an EFI partition (ESP). It contains the boot loaders or kernel images for all installed operating systems.
When a computer is powered on and booted, UEFI firmware loads files stored on the EFI system partition to start installed operating systems and various utilities.
If you accidentally deleted EFI boot partition in Windows 10, Windows will be naturally unbootable due to missing boot files.
It Is Possible to Fix Unbootable Windows Due to System Partition Deletion
But luckily, you still have a chance to make the unbootable Windows bootable again, and no reinstallation is required or at least reinstall without losing personal data. That is to recover deleted system partition or fix boot information.
Tip: Deleting a partition in Windows just clears or modifies corresponding partition information in the partition table, making Windows unable to locate the partition, and the actual partition still reside in its place until the new partition is created there. Therefore, as long as you rebuild partition table, the lost partition would be visible for both Windows and users.
Then, let's see how to do the recovery.
3 Tested Ways to Fix Windows Can't Boot after Deleting System Partition
Here, we mainly introduce 3 ways to restore deleted system partition: use a free third-party program, employ diskpart of Windows installation disc, and reinstall Windows without losing personal files.
Tip: Please try the first method, then the second one, and the last one. Try the latter only when the former failed to work.
Method 1: Fast Recover Deleted System Partition with MiniTool Partition Wizard Bootable Edition
This is the simplest method, and it perfectly worked on our testing machine.
MiniTool Partition Wizard Bootable Edition can help Windows users complete various partitioning operations when Windows is unbootable, including recover lost/deleted partition, rebuild MBR, resize system partition/boot partition, clone disk/partition, and so on.
To use this bootable partition manager to recover partition, you should purchase a paid version. If you are not a Server user, the Professional Ultimate Edition is available.
After you register the software, you can use the Bootable Media to build the boot CD/DVD discs and boot flash drive. See the guide here: How to Build Boot CD/DVD Discs and Boot Flash Drive with Bootable Media Builder.
Tip: As mentioned above, Windows can't boot after deleting system partition issue includes two situations: missing/no system reserved partition or accidentally deleted EFI partition Windows 10. Here, MiniTool Partition Wizard can help recover deleted system reserved partition and EFI partition.
Here, take how to restore system reserved partition Windows 10 as an example.
Step 1: Choose a Feature to Restore Deleted System Partition
- Run your computer from this disc that is created before.
- After a successful startup, enter the main interface of MiniTool Partition Wizard.
- Right-click on the disk where system partition was originally located and choose Partition Recovery from the context menu.
Step 2: Choose a Scanning Range
- Set scanning range for the selected disk from 3 ranges.
- Click Next.
Step 3: Set Scanning Method for the Selected Scanning Range
- You can try choosing Quick Scan at first because it requires much less time. If this method fails to find the needed partition(s), go back to this interface again and choose Full Scan.
- Later, click Next.
Step 4: Choose Searched Partitions
- Once partitions MiniTool Partition Wizard detects are listed, please check all useful partitions, both existing and lost/deleted, because unchecked partitions will be lost.
- Click the Finish button.
Step 5: Set Partition Active and Apply all Changes
- After finishing the partition recovery, there is one thing you should do. And that is to select the recovered system reserved partition and set it active.
- At last, click the Apply button to make all changes finally performed.
Tip: Here, we only show you how to restore system reserved partition Windows 10. If you accidentally deleted boot partition (EFI), the steps are the same and read this post How to Restore Deleted Windows Partition after Windows Can't Boot to learn more information.
After recovering system partition, you should be able to boot Windows again. Nevertheless, if this method fails to work, you may need to fix boot, which is our second method.
Method 2: Fix Boot Information with Windows Installation Disc
Note: We have tested the following methods on a virtual machine, which are finally proved to be useful to fix unbootable OS when Windows can't boot after deleting system partition. So, it is worth trying them, but we can't 100% guarantee that they work for you.
To use this method, please prepare a Windows installation disc which had better be the one you used to install Windows. Of course, the one holding the same version as your Windows is also available.
Then, you can start fixing.
However, since there are 2 types of system partitions, namely system reserved partition and EFI system partition, we will show operations separately.
For Legacy BIOS Users
This method will not create a new system reserved partition but do fix only. So, if you want such a partition, try other methods.
To rebuild system reserved partition in Windows 10, firstly, please boot the computer from the installation media to get the interface below:
Then, press on Shift + F10 combination keys to call out Command Prompt, and type following characters. Every type in Command Prompt, as well as Diskpart, should end with pressing on Enter key. Doki doki how to delete monika on steam.
In the window of Command Prompt, type diskpart to activate this partitioning tool. Then, type the following commands to set Windows OS partition (C drive most of the time) active:
List disk
Select disk # (# is the number of the disk where your Windows is installed)
List partition
Select partition # (Here # is the number of the Windows OS partition rather than system reserved partition)
Active
After setting the partition active, quit from diskpart.
Then, in Command Prompt please type the following commands to fix boot information to repair system reserved partition in Windows 10:
Bootrec /fixmbr
Bootrec /fixboot
Bootrec /rebuildBCD
The bootrec /rebuilBCD command will search for Windows installations not included in the Boot Configuration Data (BCD) and then ask you if you'd like to add one or more to it. Just type Yes and then quit from Command Prompt.
Then, you can take out the installation media, and your Windows is very likely to be bootable again.
Then, you can take out the installation media, and your Windows is very likely to be bootable again.
For UEFI Users
Before fixing boot, please launch MiniTool Partition Wizard Bootable Edition to view partition layout at first. In the section Fast Recover Deleted System Partition with Partition Wizard Bootable Edition,
we have introduced how to create a bootable partition manager, so here we skip this step.
Once the bootable partition manager is created, boot your computer via the disc. Then, MiniTool Partition Wizard will show you disk and partition layout.
If there is no unallocated space for EFI system partition on the left side of C drive, you can shrink your C drive via the Move/Resize Partition function to create one, which could be the size of your original EFI partition or larger.
If there is such an unallocated space, skip this step, and just select the very unallocated space, create a FAT32 partition here, and label the partition with EFI system.
Note: You can't format the EFI partition to NTFS, because UEFI firmware does not recognize NTFS.
At last, click the Apply button to make all changes executed.
The sims 1 gothic objects. After that, you can quit from MiniTool Partition Wizard and start your computer via Windows installation media. Then, press on Shift + F10 combination keys to activate Command Prompt and type the following command to repair EFI partition Windows 10:
![Daz Daz](https://www.diskpart.com/articles/images/no-boot-device-acer-7201/no-bootable-device-found.jpg)
bcdboot C:windows
Bcdboot copies boot files from the Windows partition to the EFI system partition and creates the BCD store in the same partition.
Tip: If Windows isn't installed in C drive, please replace C with the letter of your exact Windows OS partition.
Then, you can remove the Windows installation disc and restart your computer. This way is helpful to repair EFI partition when Windows can't boot after deleting system partition.
Nevertheless, if you fail to make your Windows bootable again after restoring system served partition and fixing boot information, you'll need to reinstall Windows.
Method 3: Reinstall Windows Without Losing Any Personal Files
To fix unbootable Windows after you accidentally deleted system reserved partition or boot partition, the last way you can do is to reinstall Windows 10.
Nevertheless, before doing the reinstallation, please transfer your personal files out from C drive, because reinstalling Windows will cause data loss.
Back up Personal Files from Unbootable Computer
To do this work, we recommend using the professional backup software for Windows 10/8/7 – MiniTool ShadowMaker. With it, you can easily back up your personal files even though the system is unbootable.
Similarly, you need to use Media Builder to create a bootable disc or USB flash drive, boot the PC and enter the MiniTool recovery environment based WinPE. Next, start the file backup.
Step 1: Run MiniTool ShadowMaker.
Step 2: Go to the Backup page, choose files that you need to back up and select the destination path for the backed files.
Step 3: Click Back up Now to immediately run the file backup.
PC is not booting but you want to back up files without booting to save them? This post will show you how to back up data from a computer that won’t boot.
Once the backup is completed, you can reinstall Windows without worrying about losing personal files.
How to Reinstall Windows
Windows reinstallation is not an easy thing. If you are not very clear of steps to install Windows, you can refer to the post How to Reinstall Windows 10 without CD/USB Easily (3 Skills) to get some instructions.
Final Words
Windows can't boot after deleting system partition? Now, try above methods to recover deleted system partition, repair EFI partition/system reserved partition or reinstall Windows to fix unbootable Windows 10 if it can't boot after you accidentally deleted system reserved partition or EFI boot partition.
Should you have any questions on this post, just feel free to leave us a message in the Comment part or contact [email protected].
Deleted System Reserved Partition FAQ
What happens if you delete system reserved partition?
System Reserved Partition contains the boot loader files, so Windows cannot boot properly if you delete it.
- Run MiniTool Partition Wizard Bootable Edition.
- Right-click the target disk to choose Partition Recovery.
- Choose a scanning range.
- Select a scan method.
- Choose searched partitions.
- Set the Windows partition active.
- Click Apply.
You cannot delete EFI partition in Windows 10. If you delete it, the system will be unbootable because of the lack of boot files.
It is safe for you to delete the OEM partition that is usually created by computer manufacturers. It usually contains a vendor’s software to perform a one-click factory restore setting.
QUICK VIEW: The System Reserved Partition (SRP) requirements for installing a Windows 10 upgrade, or update:
- To upgrade your device, you'll need to free up at least 15MB of space on the SRP
- If you're updating Windows 10, you need to free up at least 13MB on the SRP.
Otherwise, the Windows 10 upgrade or update will fail due to the error message [We couldn't update the system reserved partition].
Don't panic. You can easily get the appropriate System Reserved Partition space by using EaseUS partition manager as soon as possible.
Windows 10 [We couldn't update the system reserved partition]
'I cannot install Windows 10 on my computer, and it insists warning me with the error message [we couldn't update the system reserved partition]. What is the system reserved partition? What should I do to remove the error and continue installing the Windows 10 upgrade on my computer? I wish somebody could help.'
Have you ever encountered the same problem related to the System Reserved Partition (SRP) while trying to upgrade Windows 7 to Windows 10, Windows 8 to Windows 10, or simply get a Windows 10 new update on your PC? You're not alone. Here on this page, you'll figure out the reasons why you receive Windows 10 unable to update the system reserved partition and meanwhile get corresponding solutions.
Causes: We couldn't update the system reserved partition
When upgrading to, or updating, Windows 10, you might encounter the error 'We couldn't update the system reserved partition', error code 0xc1900104, or error code 0x800f0922. First of all, what leads to Windows 10 could not update the system reserved partition?
Regarding the incident of a hidden System Reserved Partition, there are mainly two reasons to meet the error during the Windows 10 update or upgrade procedure.
- 1. The system reserved partition is full, lack of free space for the system files - 80% likeliness
- 2. The system reserved partition inner error, something goes wrong with the drive
Hence, to possibly install Windows 10 updates on your computer without receiving the system reserved partition error, you should attempt to increase the system partition in the first place, and try to fix the corrupted system drive as a complementary solution. Skyrim female body texture.
Tip: No matter how you choose to fix Windows partition problems, we highly recommend you back up important personal files and data firstly, to avoid the unexpected data loss trouble.
Solution 1. Fix the system reserved partition full problem
One major reason that Windows 10 couldn't update the system reserved partition is that the system reserved partition is in low disk space for updating and installing the new system files. Therefore, to directly fix such a problem, you need to extend the system reserved partition space. For average users particularly, you must try EaseUS Partition Master Free which can resize system and non-system partitions automatically for you without losing any data.
The success of fixing we couldn't update the system reserved partition hugely depends on what fixing tools you choose. EaseUS free partition manager will be 100% helpful in extending the system reserved partition and get extra free space that required to install the Windows 10 system files on SRP.
Follow the simple steps to extend your system reserved partition now:
Using Volume Id Error Finding Your Systems Active Partition
Step 1: Locate the drive/partition
Which drive/partition do you want to adjust its size? Right-click on it and choose 'Resize/Move'.
Step 2: Resize the partition
You can either shrink the selected partition or extend it.
To shrink the partition, simply use your mouse to drag one of its ends into unallocated space. Expand the 'Advanced Settings' list, where you can see the exact disk space for each partition. Once done, click 'OK'.
Fig. 1 Unallocated space before the drive.
Fig. 2 Unallocated space after the drive.
System Reserved Partition Error
To extend the partition, make sure that there is unallocated space aside (if there isn't, follow the above steps to create some). In the same way, drag your mouse towards the unallocated space. Click 'OK'.
Fig. 3 Add unallocated space into the partition
![Error finding your systems active partitions Error finding your systems active partitions](https://www.online-tech-tips.com/wp-content/uploads/2008/12/computermanagement-thumb.png)
Night vision camera it 305wc drivers for mac. Step 3: Apply changes
At this step, you will see the new disk partition information & diagram.
To save changes, click the 'Execute Operation' button and then 'Apply'.
Solution 2. Fix the corrupted system reserved partition
Though the chance is small, It might be the Windows system partition inner error that causes Windows 10 couldn't update the system reserved partition and fail to get the latest updates. So do you know how to check and fix Windows partition errors? If you are not quite familiar with Windows disk management, you are highly recommended to use this simple repair tool again - EaseUS Partition Master Free. It allows users to check and fix partition errors within only 3 steps. Now download the software for free and follow the below guide to check and fix system reserved partition error with ease.
Guide: How to fix the system reserved partition corruption with three steps
Step 1: Open EaseUS Partition Master on your computer. Then locate the disk, right-click the partition you want to check, and choose 'Check File System'.
Step 2: In the Check File System window, keep the 'Try to fix errors if found' option selected and click 'Start'.
Step 3: The software will begin checking your partition file system on your disk. When it has completed, click 'Finish'.