I have seen crazy files but I don't remember where I saw them.
Usually files, in of themselves, is not what is slowing down your computer. Just having files on your hard drive (given it is not completely full) means very little - it's when certain things run/execute that they can cause issues.
How to perform a clean boot to troubleshoot a problem in Windows 8, Windows 7, or Windows Vista
http://support.microsoft.com/kb/929135/en-us
The less you have running all the time, the better the things you want to run will perform:
Use Autoruns to figure out what all is starting up when your computer does/when you log on. Look up anything you do not know about using Google (and/or ask here.) You can hopefully figure out if there are things starting when you computer does (or you logon) that you do not need and then configure them (via their own built-in mechanisms is the preferred method) so they do not start up - using your resources without reason.
You can download and utilize Process Explorer to see exactly what is taking up your processor/CPU time and memory. This can help you recognize applications you might want to look into alternatives for and/or get rid of all together.
Check for malware:
Download, install, run, update and perform full system scans with the following two applications:
Removing everything they find. Rebooting when needed. (You can uninstall one or both when done.)
Then perform an online scan with the eSet Online Scanner.