Resolve the "System C Drive is Full" Error in Windows Server 2019/2016/2012

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Linda 

Written by

Tracy King 

Last updated on May 6, 2024

Why is my main drive C so full?

You may receive the "Windows Server C drive is full" alert for various reasons. This issue can occur in Windows Server 2019, 2016, and 2012. Sometimes, you might also encounter low disk space warnings. When this happens, certain programs may not function properly, so it's crucial to address the problem promptly. Let's now explore the reasons behind a perpetually full C drive:

• Windows systems generate a lot of system junk files, such as cache, logs, thumbnails, downloaded files, and Internet files, on the C drive.
• You may know that temporary files (or temp files for short) can cause system crashes or slow performance, especially in Windows Server 2019/2016/2012. If not removed, these temp files can fill up your Windows Server C drive.
• Additionally, built-in Windows backup, restore points, and updates can take up a lot of space.
• If your computer has low memory, disk space can become tight too. In this case, you need to uninstall large programs to free up PC space.
• A virus or malware infection on your computer might also result in the error message indicating that the Windows Server C drive is full.

Hence, it's best to check the contents of the C drive or the server system drive that's taking up the space. If you're using Windows Server 2019/2016/2012, follow this guide to fix the issue of the Windows Server system C drive being full.

Five ways to free up space on your C drive:

#1. Extend the C Drive
#2. Clean Up Junk Files, Temporary Files, and System Cache
#3. Remove Windows.old from a Windows Server Computer
#4. Move Installed Programs from the C Drive to Another Drive
#5. Remove Viruses

How to Fix the "System C Drive Full" Error on a Windows Server Computer

Please follow the guidelines below to resolve the issue of a full System C drive on your Windows Server:

⭐Related Read: How to Fix Yellow Triangle Warning on C Drive

#1. Extend the System C Drive

The most effective way to solve the problem of a full C drive on Windows Server is to add more available space from other partitions to it. Unfortunately, the built-in disk management tool in Windows can't help you with this. You need a third-party application like tools Partition Master Server Edition to extend system C drive with simple clicks. Besides, this partition manager allows you to resize, move, migrate, and rename volumes. Also, the software doesn't require deleting or formatting any existing partitions. It can expand the target drive even if there's no unallocated space on the disk.

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Option 1: Extend System C drive with unallocated space

1. Right-click on the System C drive and select "Resize/Move." 2. Drag the system partition towards the unallocated space to add it to the C drive. Then, click "OK." 3. Click "Apply" and "Execute Task" to perform the operation and extend the C drive.

Option 2: Extend the System C Drive without Unallocated Space

1. Right-click on a large partition with enough space on the system disk and select "Allocate Space." 2. In the "Allocate space from (*) to" section, choose the system drive, then drag the end of System C drive to the unallocated space. Click "OK" to confirm. 3. Click "Perform Tasks," which will list the pending operations. Click "Apply" to save the changes and extend the C drive.

0:00-0:26 Extend the system drive with unallocated space; 0:27-0:58 Extend the system drive without unallocated space.

#2. Cleaning up junk files, temporary files, and system caches

To ensure smooth computer performance, it's essential to clean up storage space regularly. Moreover, routine system cleaning helps prevent the "System C drive full" notification in Windows Server. Let's explore different methods to clear caches, temporary files, and the Recycle Bin.

Method 1 – Remove System Junk Files using Disk Cleanup

Disk Cleanup is one of the best tools to get rid of all the junk files in Windows.

Search for “Disk Cleanup” from the search bar, select the C: drive, and click OK.

Select the drive to clean

From the “Disk Cleanup” tab, check the boxes for the types of files you want to delete. Then, click “OK” to remove the junk from your computer.

Clean up browser and thumbnail caches

Browser and thumbnail caches can take up a lot of space. It's best to clear them directly from within your browser, as this gives you more control. This will also prevent “C drive full” messages on Windows Server systems.

Open your web browser and choose to clear your browsing history, cookies, cached files, and recently closed tabs. Then, click the Clear button to delete the cache.

Cleaning up temporary files

Temporary files get stored on your hard drive, and over time, they take up a lot of space and cause your system to run slower. This is why you might be seeing the “System C drive is full” message on your Windows Server.

Press the Windows key + R to open the Run command. Type in the following text:

Next, click “OK,” and then open your Temp folder.

• Select all by pressing Ctrl+A. Next, press the Delete key on your keyboard and click OK to confirm the deletion.

This will delete all the temporary files from your computer.

#3. Remove the Windows. old Folder from a Windows Server Computer

After an upgrade, you'll typically find a Windows.old folder in the root of the C: drive. This folder contains backups of your previous operating system's program files, app data, and folders. You can delete it – assuming everything else is working fine – to free up several gigabytes of space.

However, you should note that this method will remove previous Windows system backups if you plan to create a System Restore Point. Thus, you might choose to back up the operating system to an external hard drive. You can opt for Todo Backup Enterprise to back up your operating system. It runs reliable system backup software to back up the operating system to an external hard drive. In addition, it features some innovative functions and offers four editions to meet the needs of different business environments.

In this article, we will see how to delete the Windows.Old folder to avoid the C drive full issue in Windows Server systems.

You can use the Disk Cleanup tool to remove the large Windows.old folder that contains the old operating system. However, if you don't have the Desktop Experience feature installed, you won't be able to access it. Therefore, you can use a command-line utility with administrative privileges to delete the item. To do this, use the following command:

> Take ownership of everything in c:\Windows.old and all its subfolders, recursively, with administrator permissions, and confirm that you have permission to delete.

Set permissions to " Administrators:F " for all files and subfolders under C:\Windows.old.

Deletes the C:\Windows.old directory and all its subdirectories and files (requires administrator permission).

Disk cleanup utilities can also do this. Follow these steps:

1. Open File Explorer from the Start menu on Windows. Then, click the "This PC" icon. Right-click the drive that contains the Windows or Windows.old folder, and select "Properties" from the menu. 2. Go to the "General" tab, and then click the "Disk Cleanup" button to start the process. 3. Click "Clean up system files." 4. A list of system files that can be deleted will appear. Next, check the box next to "Windows Update cleanup," and then press "OK" to confirm your selection. This will remove all data associated with your previous version of Windows, including the windows.old folder.

#4. Move Installed Programs from C Drive to Another Drive

It's recommended that you frequently transfer some files from the C drive to other drives to save space. This will also prevent you from getting the "C Drive Full" notification in Windows Server. However, you can use third-party software like Todo PCTrans to help with file migration, as it fully supports all Windows operating systems and various laptops and desktops. Additionally, this software offers an application migration feature, allowing you to change the installation location of your favorite programs without needing to reinstall them.

Step 1: Run Todo PCTrans on your computer

Go to "App Migration" and tap "Start" to continue.

Select the app migration transmission mode

Step 2: Move the program to another drive

1. Select the C drive and check the programs you want to move (labeled "Yes").

2. Click the triangle icon and select another disk on your computer as the target location, then click “Transfer” to start the process.

Select the apps to transfer

Step 3: Complete the transfer

Wait patiently for the transfer to complete, then click OK to confirm.

When it's done, if necessary, restart your PC, which will preserve all the changes on your PC and allow you to run the program from another hard drive without having to reinstall.

Step 5: Clean Up the Malware

You should always use an antivirus software to clean viruses and malware that cause the Windows Server message to show up, stating that the C drive is full.

Conclusion

It's always good to manage your disk space well so that you have enough room and avoid the "System drive is full" error message in Windows Server. However, you can easily reallocate disk drive space using the Server Edition of Disk Partition Master Tool.