I hope this is in the right area.
I've been working on my grandfather's computer for a day or so now, trying to figure this problem out.
My sister's friends downloaded all sorts of games from obviously not very good sites. I don't live here, so I'm not sure exactly what she did, but it messed up the computer pretty good!
I've had several problems with it (some I've solved), but the biggest that NOTHING has seemed to fix is that the desktop icons will not open when double-clicked. Neither will the folders in Windows Explorer. I can right click on all of them, and they give me the option to "Open" and then they open just fine. (Last night, I could double click on My Documents, My Computer, and the Recycle bin and they would open (from the desktop), but now NONE of them work.)
I have looked for help all over, have tried several different things (including using this for .exe and short-cut behaviors: http://www.dougknox.com/xp/file_assoc.htm
I ran Malwarebytes, three times now (the first time it picked up 108 items, the second them ~53, and the third time I ran it in Safe Mode and it picked up none.) I also ran SuperAntiSpyware in Safe Mode and it picked up on and got rid of 2 things.
I cannot do a system restore, as I've tried several times and none of the points want to work.
And I've also followed a few guides going through the CMD and regedit, to no avail.
I tried a different mouse, and that one didn't work either. However, both mice can double-click and open the files in Safe Mode.
(Aside from this, Internet Explorer will open and then instantly close. I've also tried a dozen different things to fix this, but with no success. But I suppose that's for a different thread.)
If anyone wants information on what was happening directly after my sister's friend added everything, I can try to explain in the best detail possible, though I was only here for a little bit of it and am not sure I 100% know everything.
Sorry for such a long post! I just wanted to try to put as much information out there as possible.