The mystery of the missing 20.5 GB of hard disk (z60t)

[cl]

It all began when I Right Clicked the C: drive and it showed 39.8 gb used. Very strange since there is no data on the laptop. So I googled disk software and found a trial of Size Explorer Pro 3.8.5. When I ran it, it shows only 19.3 GB used which is what I would have expected. All that's on the machine is XP, Adobe Creative Suite and Microsoft Office 03. No documents, pics, videos or games.

Hmm, 20.5 GB of a 60 GB drive seem to be missing.

Rechecked my Settings to make sure Bill Gates wasn't protecting me but all the naked settings were active:
Show Hidden Files and Folders is ticked
Hide Protected Operating Systems is unticked

So then I ran Ashampoo to make sure all the rubbish was cleaned out. That got me a gig, but no where near the 20 gb still missing (actually when I began it showed I had only 9 gb free. Now it's up to 12, but it should be 32).

Even did the disk check which took ten minutes at reboot to declare all in good health.

What is the secret to get into the hard drive and find how IBM is protecting me from myself?

Some other strange things. This is a limited use laptop. I am writing a book and now use a 4 gb jump drive to use InDesign to edit the book when I am on the ferryboat to town. A while back it came up with a missing DLL error, which became serious when I had to upload a draft of the book using a Starbucks wifi. To make it work I had to reload windows, which blew out all my InDesign upgrades. Finally got it all working.

When I went to set up screensaver with pics from the book, I noted that a lot of the folders that held photos from the book now showed nothing in them, so I deleted the folders. There is virtually no data on the machine, only programs.

Anyone know how to actually see what is on the hard drive? My guess is that it has created a mirror backup, or has stored lots of backups (although I told it to get rid of them)

[GomJabbar]

You can boot up in SAFE MODE and check for a folder called C:\rrbackups. If there are any R&R backups saved, they should be there.

You can look in C:\Windows for any $NtUninstallKBxxxxxx$ folders for uninstalling (and rolling back) Windows updates.

System Restore can use quite a bit of hard drive space. Right-click on My Computer and choose the System Restore tab to effect changes. You can turn off System Restore and all your previously saved Restore Points will be deleted.

You can run the Disk Cleanup. Open My Computer then right-click on the C: drive and choose Properties, then click on the Disk Cleanup button.

Occasionally some log files can grow to be quite large. You could do a search on your hard drive for all files over a certain size - say perhaps 1 GB.