Perhaps your Windows registry database contains wrong data on location of user special folders. Hopefully you can fix this using the procedure provided here:
LOTS of Windows 7 users have trouble with Skype versions 6.2 and up. These upgrades cause Skype and any other running programs to freeze. Uninstalling 6.2 and then reinstalling the previous 6.1 version was the suggestion offered in another Skype forum for Windows 7 users with a comment that "Microsoft engineers are working on this problem for later versions". But unstalling the new 6.2 and then reinstalling the old 6.1 did not solve the problem; my computer still froze. The *only* way I could find to fix this incapability was to use my Windows System Restore and go back to a point in time before I downloaded the 6.2 "upgrade". Now everything works fine again (except I get that Skype popup "update" every time I launch Skype), but I simply click "Not Now". I am certain that LOTS of Windows 7 users (and there are *many* of them) have this issue. Just as with aol, when a large internet service takes over a smaller one, the software in furture versions gets buggy. I hope Skype does not go the way of aol's ICQ and Netscape because of Microsoft screwing it up.