Windows 7 - Weird assortment of dll, permissions and Graphics Driver errors

Hi all,

Sorry, bit of an essay to read, but the problems quite weird!

This morning, it booted with a blank black desktop. The black desktop remained regardless of which theme I chose, so I went to Google a solution. When opening IE, it stated along the lines of "A program has corrupted your default search provider, so IE is resorting to the standard (bing)." Interestingly, it never did switch, but the message was a nuisance. I tried a simple fix for the desktop which included a restart, and BAM! On restart, several screens of text zip past mentioning about scanning "C:" and deleting\repairing various registry entries I think (didnt have time to properley read it :S ), and it restarted again. This time, it loads fine, but the black desktop remains, I get an error from Dropbox, saying it has no permissions to start, and from Open Office saying it has had a fatal internal error. (Probably shouldnt have either of these starting up on logon, but meh). Wierdly though, IE gives one more stupid error about switching default browser, and since then its little problem seems to be fixed.

Still googling the black desktop, the program errors, when I notice most of my icons in taskbar have defaulted to the blank piece of paper icon, and later still, while looking at my "Application Data" folder (in my user folder), I notice it's now called "pplication Data", but of course I can't change it back since it's almost always in use! The strangeness grows when I try and make a new folder called "Application Data" and it says one already exists!!! Is there an "A" or isn't there!?

So, I'm fairly concerned I'll have to do a complete system restore or something, but I was wondering what on earth has gone wrong with my PC?

(Oh, and no new programs/notable downloads in the past few weeks, and an AVG scan came up clean, so doubting a virus)

Thanks for any tips, tricks, suggestions or input!!!

MC x