Mysteriously full hard drive

[Hodsocks]

Can anyone shed any light on a problem I looked at over the weekend? The guy tells me that he went out in the morning and his computer was working fine, using about a quarter of the hard drive space (160GB) when he came home his computer was very slow and his drivehad only 2GB of space. Noone had used it during the day as he lives on his own. We have run Mcafee, Malwarebytes, Combofix and Ccleaner and cleaned out some stuff but nothing much.
I checked all his files and directories and the evidence suggests that there is only about 30 - 40GB on the drive so what is filling it up? I unhid all the files before I checked what was on the drive incase something was hidden.
I ran diagnostics on memory and drive and everything seems to be fine, I have fixed it by formatting and reloaded the software, although I boticed that the format seemed to take much longer than I expected.
Have any of you guys experienced anything like this or have an idea what was filling the drive because it had me beat.

 

[DelJo63]

first run CLEANMGR (start->run->cleanmgr) for the Admin ID and then again for the private user-id (runas /user:whatever cleanmgr)

verify free space and then consider reconfiguring the System Restore to a smaller percentage.

 

[LookinAround]

C:\System Volume Information folder is sometimes the culprit. That's where System Restore points are saved. (fyi... it;s both a hidden folder and even admin can't see its size or content by default!) So Windows explorer will show 0 size even when it is really many Gig in true size

To empty the folder, turn off System Restore points. Then turn them back on.

Or, if you want to actually see that folder's true size you should have Administrator "Take Ownership" of that folder (google Take Ownership)

/* edit */
I've sometimes seen Windows exceed the supposed limit one sets on System Restore space (by default is 15% of disk space). Turning System Restore off then on, empties the folder. You might want to run a System Restore point manually after its cleared, so you have one

 

[Punkid]

try CCleaner , it can remove restore points too...thats your best bet

 

[LookinAround]

try CCleaner , it can remove restore points too...thats your best bet

Thanks Punkid

i've been using CCleaner for years but never noticed one of its tools (Tools->System Restore) lets you list and remove old system restore points. Handy. thx