By Dervish / Last Updated March 10, 2022

Hard drive keeps filling up on Windows Server 2012

Many users complain that their Windows Server 2012 (R2) hard drive keeps filling up, which has a bad effect on system boot-up, documents open-up, software installing, game loading, etc. Obviously, it would be quite annoying as well to get Low Disk Space warning popping up when you are concentrated on work or other stuff on Server. What’s worse, the important data on host computer and client computer may also be affected if a Server that serves the company running out of space.

Therefore, with so many inconveniences caused by Windows Server 2012 disk full, it is very urgent to figure out how to solve this problem. But before that, you may want to know what on earth “eating up” disk space.

What is taking up space on Server 2012 system disk?

Different situations may result from different causes on Server 2012 R2 system disk filling up. Some users said that C drive keeps filling up even if there are no files add in. That is to say, Windows Server 2012 disk space incorrect. Fortunately, hard drive status can be easily displayed by some analysis tools, Windirstat (Windows Directory Statistics) and TreeSize.

In a nutshell, the following contents would be the main cause for low disk space warning on Windows Server 2012, backup files, System Restore Point, paging file, hidden files, and temp files of some software.

System Restore Points is created by Windows Server itself. By default, the System Restore Points are set to take up 50% of disk space and stored at system drive. Go System > System Protection > System Protection Tab > click on the C drive in Protection Settings and then the Configure. It will show you the slider with how much space is being used.
As for temp files of installed software (you can tell that with the help of the aforementioned software), you can try deleting the temp files or uninstalling that software to free up disk space. Well, what specific measurements should you take?

Windows Server 2012 (R2) running out of disk space: How-to fix

As covered before, different situations require different solutions. Below paragraphs discuss this issue from three perspectives of view, and corresponding fix methods are followed.

Windows Server 2012 clean up disk space

Delete unnecessary files, cache files, junk files, empty recycle bin, or uninstall the software that you do not use for a long time can apparently increase free space on the hard drive. In terms of paging files, you can change their location, for instance, from C to D drive. Disk Cleanup removes temporary junk for the most part and only works its magic on the C drive.

Step 1. Open This PC, right-click C drive and select Properties. Click “Disk Cleanup” to calculate how much space you will be able to free.

Disk Cleanup C Drive

Step 2. Tick the files you will delete and click “OK”. Then confirm at the pop up dialog.

Files to delete


You need to enable Server 2012 Disk Cleanup utility through “Add roles and features” if you did not use this feature before.

The free space may be fully occupied in the near future given that you do not disable system restore. If concern about the system protection after System Restore disabling, you can backup system to external hard drive with the help of free AOMEI Backupper.

Windows Server 2012 R2 C drive full

Except for factors mentioned before, Windows Server 2012 C drive out of space could be the result of limited partition size. Windows Server 2012 minimum disk space is 32 GB (system partition) according to Microsoft. And computers with more than 16 GB of RAM will require more disk space for paging, hibernation, and dump files. As time goes by, the system C drive can be filled up easily.

You can extend C drive with Computer Management in Server Manager. However, if the unallocated space is not adjacent to C drive or there is no unallocated space on the hard drive, it is time to seek help from other partition tools, for example, AOMEI Partition Assistant Server. This is a Server partition manager that created for Windows Server OS in particular. It can work with Windows Server 2022/2019/2016/2012(R2)/2008(R2)/2003. The steps are very easy to follow.

Tips: If there is unallocated space on the hard drive and does not adjacent to C drive, try Merge Partitions on Server 2012. Below takes allocate free space from existing partition for example.

Step 1. Run AOMEI Partition Assistant Server. Right-click the partition that has redundant free space and select “Allocate Free Space”.

Step 2. At this page, specify the free space and select the target drive as C. Finally, click “Apply” to execute.

Allocate Free Space From D To C Drive

▪ This operation will be done under Windows PreOS mode, so a reboot is necessary.
▪  If you don't want to resize C drive, you can move apps from C drive to another drive that has much unused space via App Mover function. 

Windows Server 2012 increase disk space via disk upgrading

Sometimes, it is not the problem of stored data or partition size but the hard drive capacity. If the Server hard drive is old enough and too small to store all data created by your daily computing, you’d better upgrade it to a larger one. The “Disk Clone Wizard” in AOMEI Partition Assistant Server will assist you to move everything from the old hard drive to the new one without reinstalling and data loss.

Step 1. Connect the new drive to your Server 2012 and make sure it can be recognized. Start AOMEI Partition Assistant Server and right-click the system disk and select “Clone Disk”.

Select Copy Disk

Step 2. Select the copy method based on the prompts.

Disk Copying Methods

Step 3. Select connected new drive as the destination disk.

Select Destination Disk

Step 4. You have options to edit partitions on new drive if you selected “Clone Disk Quickly” before.

Edit Partition Size

Step 5. There is a note says something about boot up Server 2012 after cloning. Then preview the outcome, click “Apply”>“Proceed” to commit the pending operation. Wait for the process to be completed.


Step 6. Shut down the Server to change boot priority to new hard drive in BIOS. Or, you can remove the old hard drive and keep new drive installed to test if it is bootable.

Change Boot Priority

Tips: If clone hard drive between MBR and GPT, you need to change boot mode between Legacy and UEFI/EFI (Legacy for MBR and UEFI/EFI for GPT). Or, convert MBR to GPT on Server 2012 before you start.


Windows Server 2012 hard drive keeps filling up could be the result of many different elements. Therefore, you need different workarounds in different cases. AOMEI Partition Assistant Server is an all-around Server disk partition manager that comes with many helpful features. For example,  after migration to a new disk, you can create a bootable disc with it and format C drive as well as the entire disk in Windows PE or Linux. 

Besides, the AOMEI Partition Assistant Unlimited and AOMEI Partition Assistant Technician have a useful feature, Create 11 Portable Version, which can create AOMEI Partition Assistant to a removable device, such as USB flash drive. Then, you can connect the device to other computers and run AOMEI Partition Assistant from the device without installation.