I recently restored my computer back to factory settings (clean os) after screwing it up, but I kept source 2007 shared materials.gcf, source 2007 shared models.gcf, source 2007 shared sounds.gcf, source materials.gcf, source models.gcf, source sounds.gcf, team fortress 2 client content.gfcf, team fortress 2 content.gcf, and team fortress 2 materials.gcf on a 16 gb flash drive, so I could just verify integrity of local cache and not have to redownload 13 gb of stuff. I've done this before on moving from windows -> ubuntu, but it's been stuck at 100% verification for 4 or 5 hours - validating Steam cache files 0 out of 1, validating Team Fortress 2 file 1 out of 1. I've already tried cancelling and re-validating before, to no avail.
OS: Windows 8 64 bit