Ok.... need some help.

[Ace]

I've been having some trouble lately with my pc, and I was wondering if anyone might know something that I don't.
I went to routinely restart my pc one day, and ever since then, it's been acting very strange. For example, on the desktop, this random "most common tasks" thing has popped up. And, for the life of me, I cannot figure out how to make it go away. I've tried looking in all the display options, folder options, etc etc. And I can't find anything that will make that thing go away. I've tried right clicking it, left clicking and dragging,...... everything! Nothing works. So that's one problem.
The next is, since that day, the icons on my desktop are locked. Like I did with the "most common tasks" sidebar, I looked through all the options to let me move them at will, and still nothing. I tried unchecking the box that says "lock desktop items" (or something like that) and that didn't work. So, there's another problem.
Lastly, I can't uninstall most programs on my pc. For most programs, when I go to uninstall them using Add/Remove programs, it tells me "Could not locate Install.log file." I don't even know where to begin here....besides re-installing every single program that is missing the log file.
So, if someone could help, it'd be much appreciated. If you live here in Marietta, and you help fix my pc, I'll get you some free food from Arby's. Thanks in advance!