You're off topic for this forum, which is dedicated to Windows Live OneCare. You may want to try the Windows XP newsgroups here: http://support.microsoft.com/newsgroups/Default.aspx
By the way, I just repaired a PC that was infected by thousands of pieces of malware - trojans, viruses, you name it - and the way I got the desktop back was to perform a System Restore back to a time when the desktop was normal on the PC. Then I went about cleaning it up.
-steve