Windows Server 2025 C Drive Low Disk Space Alert/Solution

Many server administrators report that the C drive runs out of disk space on Windows Server 2025 after installing updates. As with other versions of Windows, this is a common and frustrating issue. As more programs are installed on the server and Windows Updates continue to be downloaded, various files can quickly consume disk space. These include temporary internet files, browser caches, logs, downloaded files, Windows shadow copies, and restore points. This article explains how to enable and disable low disk space alerts on Windows Server 2025, and how to resolve this issue quickly and easily.

How to Enable Low Disk Space Alert on Windows Server 2025

1. Press Win + R on the keyboard, type "regedit", and press "Enter" to open the Registry Editor.
2. Go to the following registry key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer
3. Inside the Explorer key, right-click in an empty space and select New > DWORD (32-bit) Value.
4. Name the new value "NoLowDiskSpaceChecks".
5. Set its Value data to 0 to enable low disk space checks and notifications.
6. After making the registry change, restart your server for the settings to take effect.

You can also create a simple PowerShell script to monitor the disk space of the C: drive and send an alert when free space falls below a certain threshold.

How to Customize:

• Threshold: You can change the $threshold variable to a different value if you prefer a different free space percentage (e.g., 5 for 5%).
• Action: You can add an action, such as sending an email or logging the warning, by modifying the script further.

To automate this script, you can use Windows Task Scheduler to run it periodically (e.g., daily or weekly).

How to Disable Low Disk Space Warning on Server 2025

It is recommended to enable the low disk space alert on Windows Server 2025 so you can take proactive measures. However, if the alert is malfunctioning, or if you simply prefer not to see it, you can disable the low disk space warning on the server. To do this, change the registry value mentioned in step 5 to 1, or disable/delete the scheduled PowerShell script.

How to Resolve C Drive Low Disk Space Issue

There are two effective methods to resolve the C drive low disk space issue on Windows Server 2025.

Method 1: Remove Unnecessary Files

The C: drive often accumulates a large number of junk and unnecessary files. While deleting these files is recommended as a first step, it may not yield a significant amount of recovered space and isn't a permanent solution. Follow the steps below to free up disk space on Server 2025:

1. Press Windows + R on the keyboard, type "cleanmgr", and press "Enter".
2. Select the C: drive and click OK to continue.
3. In the next window, select the checkboxes for the file types you want to delete and click OK. Generally, all the listed files can be deleted safely.
4. Click the "Delete Files" button to confirm the deletion.

If you want to delete all unnecessary files in one step without selecting them every time, type cleanmgr /VERYLOWDISK and press Enter.

Method 2: Move Free Space to C Drive

Even when the C: drive is running out of space, there is often plenty of free space on the D: drive or other data partitions. You can shrink the D: drive (or another volume) using disk partition software to create unallocated space, and then extend the C: drive by combining it with this space. This approach restores a large amount of free space to the C: drive. This is the most effective method to resolve low disk space issues on the C: drive in Windows Server 2025 and other versions.

Download NIUBI Partition Editor, and follow the steps in the video:

To accomplish this task, reliable disk partition software is required. Compared to other tools, NIUBI Partition Editor is much safer and faster because of its powerful technologies:

• Hot Clone: Clone disk partitions without interrupting the server. You can clone the system disk before making changes or as part of a regular backup routine.
• Virtual Mode: To prevent mistakes, all operations are listed as pending for preview. Real disk partitions are not changed until you click "Apply" to confirm.
• Cancel-at-will: If you initiate an incorrect operation, you can cancel ongoing tasks without worrying about partition damage.
• 1-Second Rollback: If any known error is detected while resizing partitions, the software automatically reverts the server to its original state instantly.
• Advanced File-Moving Algorithm: Resize and move partitions 30% to 300% faster, saving significant time, especially when handling a large number of files.

In addition to shrinking, moving, and extending partitions on Windows Server 2025/2022/2019/2016/2012/2008, NIUBI Partition Editor helps you perform many other disk partition management operations. Explore the detailed features of this tool or watch the video tutorial to learn how to use it.