Windows Server 2008 system C: drive full

Updated on: July 11, 2019

This article introduces why system partition C is getting almost full in Windows Server 2008 R2 and how to fix C: drive full issue on Server 2008.

Why C drive is getting full automatically?

Many Windows 2008 servers keep running several years, the hard disk is not big when installing the Operating System. Some server administrators have replaced the disks with larger ones or hardware RAID arrays. However, many people still feedback that the system C: drive is almost full.

As we know, many types of files are saving into C drive continuously, for example: Windows Updates, applications, temporary files, logs, cache, etc. If C drive is not big enough or you do not remove junk files regularly, of course C drive becomes full sooner or later.

Unlike Windows Server 2012 and 2016, Server 2008 doesn't change C drive to be red in File Explorer when it is running out of space. Therefore, many people don't pay attention to disk space usage until receiving "Low Disk Space" alert. C drive full is very dangerous to a server, because server is very likely stuck, reboot unexpectedly or even crash. You'd better fix C drive full for Server 2008 as fast as possible.

How to fix C drive full issue?

When system C: drive is getting full in Windows Server 2008 R2, there are 2 main steps: clean up disk to reclaim free space and enlarge C drive with partition software.

Windows Server 2008 has native Disk Cleanup utility can help you delete unnecessary and junk files to reuse disk space. It is able to remove most common types of junk files fast and safely.

After freeing up disk space, you'll get free space more or less, then server could keep running in the right way. In addition, there is free space to install programs that help fix system partition full issue.

1: Free up disk space

To free up disk space on Windows Server 2008, the built-in Disk Cleanup utility is the first choice. There are many third party optimization software, but Disk Cleanup is the safest. Don't put the server into danger for additional 1GB space.

Steps to free up disk space in Windows 2008 server:

  1. Press Windows and R together on the keyboard, type cleanmgr and press Enter.
  2. Select C: drive (or other one) in the drop-down list.
  3. Click the check-boxes in the front of the files that you want to clean.
  4. Confirm in next window.

If you receive error that Windows cannot find cleanmgr, it means that you have not enabled Disk Cleanup. Follow the steps to install Disk Cleanup on Windows Server 2008.

Generally speaking, you'll get several gigabyte free space in C drive, few servers that never freeing up disk space before may reclaim over 10GB free space.

However, you can't solve this problem completely, because the free space will be eaten up quickly by new generated junk files. This is the reason why many people find C drive full again in the near future. You'd better add more free space from other partitions.

2: Add more free space to C drive

All hard drive partitions are allocated while installing Windows, but you can change partition size without losing data. Shrink D or other volume that has plenty of free space, then part of unused space will be converted to Unallocated. This space can be combined to other partitions in the same disk. In this way, there will be plenty of free space in C drive again, Operating System, programs and associated settings, Windows services and anything else keep the same with before.

Download NIUBI Partition Editor and follow the steps in the video to expand C drive by moving free space from other volumes:

Video guide

If original disk is too small, so you cannot reclaim or add enough free space from other partitions, you may clone to a larger disk or RAID array. While copying you can expand system partition (and other volume) with extra disk space.

In Summary

When system C drive is getting full in Windows Server 2008 (R2), try to fix this issue as fast as possible, otherwise you'll suffer from server performance down, system stuck or crash.

To solve this problem, freeing up disk is not enough, you'd better add more free space into it, especially to the server that C drive or the entire disk is small. To remove the new generated junk files, you'd better run Disk Cleanup once a month.