Well before you do that, let's just try this:
Download and install Spybot Search & Destroy
. (Click 'Download Now')
Now run the install, install everything but Teatime (it becomes a hassle and isn't needed if Norton is present). Once installed, run the program and install updates. (Follow the tutorial windows that pops up on the first run and create a registry back-up, etc)
When you update it, it should close the program open a command prompt and do what it needs to. More than likely, when the program starts up again, the tutorial won't be there, so once its loaded, go to 'Update' and make sure it has all the updates and then go to 'Immunize' and it'll tell you "0 products are blocked, xxxxxx aren't" or something like that. Click 'OK' and than click 'Immunize'.
NOW...go to 'Search & Destroy' and click 'Check for problems'. It'll now scan your computer and this might take a while depending on the computer, memory, etc.
If problems come up, clean them. Than try closing a window again and if it still happens, Run HJT and post a log. DO NOT POST A LOG IN THIS THREAD!!!!
Only post in the HijackThis Logs and Analysis
Once posted, a certified HJT specialist will help you.
Hope this helps,