Win32:Spybot-z

I’m having trouble getting rid of a virus on my machine. The Avast scanner catches it everyday and deletes it, but it seems to keep coming back. I suspect it’s using the Windows Update function to reinstall itself. I keep getting a pop-up from WinXP telling me new updates are ready to install. The machine does not ask to restart afterwards however, like it normally does. Shortly afterwards Avast catches this Win32:Spybot-z worm on my computer. I’m pretty sure I caught this virus from some program I installed off the internet. :-[

Question: How do I get rid of this Virus once and for all?

PS. I searched for answers all over the internet and couldn’t find anything. If anyone can help it would be greatly appreciated.

That is not so easy to answer to. Some of the Spybots infect their victims by scanning the Network/Internet, some of them “get dropped”(?) by other Software. One thing you can do is to delete the file in windows safe mode and close all your open shares. If that will not solve the problem you have to search for a Fle who dropps the Virus. Therefor you have to check the files which will be loaded on Startup.
Or you can try this onlinescanner http://www.ravantivirus.com/scan/indexscan.php?
or this one: http://us.mcafee.com/root/mfs/default.asp?WWW_URL=www.mcafee.com/myapps/mfs/default.asp

Some infos about “your” Virus: http://www.virusbtn.com/resources/vgrep/vgrep.cgi?terms=spybot-z&product=0