DrWatson is the debugger built into Windows, which is being triggered because of an unexpected severe error (probably in your registry).
I'd be very careful with registry cleaning programs at this point, because Windows won't always crash out the program that gracefully. Some severe registry problems will end in a blue screen of death (typically, PAGE_FAULT_IN_UNPAGED_AREA). At any rate, there is something not right going on.
I'd start out by doing:
Start > Run >
chkdsk C: /RA black console window will open, and chkdsk will tell you that it can't check the volume because it's in use by another process, and will ask you if you wish to schedule it for the next system restart. Type a
Y, and hit enter. chkdsk /R can take up to 2 hours to complete.
Then go into event viewer:
Start > Run >
eventvwr.mscRight-click
Application, and choose
Clear all events.
Do the same thing to
System.
Then run CCleaner again and get it to crash again and shut it down the same way you have been doing it.
After DrWatson and CCleaner are gone, go back to
eventvwr.msc again. Right-click on
Application, and choose
Save Log File As.... In "Save as type", choose
CSV (Comma delimited) (*.csv) and save it to your desktop. Do the same for the
System log. Go to
http://upload2.net/multiple_upl.php and upload both files, and post the download links it gives you so I can take a look.

edit: upload2 sucks; I can't ever download anything from it. Don't use it. Find another online file-hosting service.