I have never had a problem with this computer in the year and a half that I've had it, but over the past day it has exhibited some strange behavior. The worst of it is that it loads incredibly slow and freezes altogether. And Google searches have been impossible. Whenever I click a link, it loads a separate tab and either takes me to a "click fraud" test or redirects me to another site or search engine. It never loads the corresponding page. Even if I copy the URL, there's no guarantee that it will load: I sometimes get page load errors for certain sites. When I turn the computer on, I sometimes get a data execution prevention error that says "generic host process for win32". And for some reason another user account has appeared on Windows start up. The user name is a long string of letters and numbers. The strange thing about all of this is that sometimes it will act up and sometimes it won't. My computer just froze twice in a row, once on boot up, but I didn't get the DEP error this time, and my computer is loading and running fine even though it was just acting up on me. Chances are these problems will soon return. I have ran several anti virus and spyware programs, but even when it clears everything out, I am still experiencing problems. I'm not the only one who uses this computer, and I'm almost certain that the problems started when someone else was using it. I wouldn't doubt that there are multiple problems, but I have no idea where to start. It seems overwhelming right now. Does anyone have suggestions? Thanks in advance.

I guess I should have checked the Google redirect thread more thoroughly before posting because Malware Bytes cleared up some issues. And the DEP thing hasn't shown up lately. Would it be prudent to post a Hijack This log?

It is most likely that you have spyware, or worse - maybe theres a rootkit on there - i would suggest you use hijackthis (which you can find at a website called majorgeeks) and learn to use it. Also use a tool called smitfraudfix. Before doing that click start click run Type: msconfig look at the start tab and disable anything you dont need or google what you dont recognise and disable it if you dont need it - also look at the services tab and click "hide microsoft services" then from whats left disable any that are obvious malware - research the rest on google and disable as necessary