Tortoise SVN/Windows 7 seems to have lost folders - completely stumped

Have Tortoise SVN (Shell Extension) and Slik SVN (Command line) install开发者_运维技巧ed on Windows 7.

Attached a USB drive, did a get on a 100GB source code library. Tortoise sucked up 50% of CPU trying to keep it in synch, as it was a backup told Tortoise not to synch it.

Disconnected the USB drive.

Hooked it back up a few days later - my repository is gone.

Chkdsk /F -- no errors on drive.

Add up the total files, I get 320GB, but the drive shows 420GB in use so the repository is there alright.

I'd like my repository, or my 100GB back without having to reformat the drive. No, it's not in the recycle bin... No it's not a different user. I have admin privs on the box anyway.

Gave up and formatted the drive...

What I did was an svn get, and then told Tortoise SVN to exclude the drive, unplugged the drive, plugged it in a week later, nothing there.