What to do when C drive is full?

Most of Windows computer users will encounter this problem that system C: drive is full and running out of free space. It is troublesome, as nobody would like to start from scratch, keeping in danger of losing data. Every problem becomes easier to be solved if you doing right thing. Many users feedback this C drive full issue, but after searching by Google, there seems to be no complete solution, so here I want to give some advice about C drive is full and running out of space.

Why C drive becomes full rapidly?

Actually, no matter you use Windows Server 2016/2012/2008/2003 or Windows 10/8/7/Vista/XP, you are very likely to encounter the C drive full problem sooner or later, because:

  1. Windows updates continuously save to C drive.
  2. Temp files and caches are save to C drive by default.
  3. All applications install to C drive by default.
  4. Some files still write to C drive even if you set to install applications to data drives.
  5. Recycle Bin grows every day after you deleting files.
  6. Hibernation and System Restore service can eat up large amount of free space.

Symptom of C drive full

Windows XP and Server 2003/2008, if system C drive becomes full, it displays the low disk space warning at bottom right corner – “You are running out of disk space on Local Disk (C:). To free space on this drive by deleting old or unnecessary files, click here.”

C drive full

In Windows Vista and later editions, C drive shows red instead of default blue when it is running out of free space in “My Computer”.

C drive red

Whenever you see the Low Disk Space warning or C drive red bar, you should try to solve this problem as fast as possible, because it causes many issue in this situation.

What happens if C drive is full?

  1. System runs much slower.
  2. No space to install critical Windows updates.
  3. System may be crash if there is extremely low on disk space.

Solution of C drive is full or out of space

When system C drive is running out of free space, the first steps is freeing up to reclaim some free space, and then expand C drive with the unused space in other drives. If there is no other drives, or no free unused space space all other drives, try to clone and migrate to another larger disk.

1. Free up disk space

The first choice to free up disk space is Windows built-in Cleanup utility.

  1. Open My Computer
  2. Right click C: drive and click Properties
  3. Click Disk Cleanup
  4. Select the files you want to safely delete

You may also use 3rd party software to scan the whole disk partition and delete the files you do not need.

2. Extend system C drive

If you cannot free up large amount of space from C drive, you’d better expand it with free space in other drives. Otherwise, you’ll encounter the C drive full problem near future if the free space of C drive is not enough.

Step 1: Download and install NIUBI Partition Editor, right click drive D: and click “Resize/Move Volume“.

Extend volume

Step 2: In the pop-up window, drag the left border rightwards to generate free Unallocated space.

Shrink d drive

Drag to resize

Click OK and back to the main window, where 20GB Unallocated space created behind C: drive.

Volume shrank

Step 3: Right click C drive and select “Resize/Move Volume” again, in the pop-up window, drag the right border rightwards to hold the Unallocated space.

Extend C drive

Extend volume

Click OK and back to the main window, where C drive extended to 50GB by holding the 20GB free space from D. Press Apply on top left to execute, done!

Volume extended

If there is not enough free space in D, you may get free space from other drive in the same disk.Learn More