Disk Cleanup does not delete windows update files

DavidE said:

You might not have enough free space on [C] to run Windows Update cleanup ???
Did you look in Event Viewer to see if there are any errors ?
If you have hibernate turned on, turn it off, at least temporarily.
If you can temporarily move any User data to another drive to free up space, try that.
TFC is a more thorough temp file cleaner, and it's a "portable" program (no installation required).
TFC - Temp File Cleaner by OldTimer - Geeks to Go Forum

Thanks from a fellow NC'er! I had ~4GB that would not clean and when I turned hibernation off, I somehow gained ~6 free.

Laffer said:

Well, I'm glad to say the problem has been finally solved. Indeed there was not enough free space on C:. Luckily disabling hibernation gave enough free space, because I wouldn't have had anything else to remove as the partition already consists basically only of system files. Windows 7 really loves eating up the GBs. Thanks to DavidE and everyone else who were being helpful.

I encounter the same problem. Disk Cleanup says that I can free 7.18GB, but the progress bar disappears in the middle and nothing happens (also after restarts and running as admin). I'm pretty sure that I have the same problem as Laffer, as I have only 3.76 free GB on my hard drive. The problem is that this is a 102GB hard drive, so no matter how much space I try to make (uninstalled pretty much every program I had installed, cleared all temp files I could find, disabled hibernate etc.), I still couldn't free enough space for Disk Cleanup to work, as Windows folder itself takes the vast majority of the used space.