I did a Google search for Trojan.Vundo and most of the sites note that it is difficult to remove. They all require a download of one or more programs to remove all traces of the trojan. However, I don't know how current these articles are, so I would be cautious about proceeding with them.
SUPERAntiSpyware says that it can remove the trojan without any download. This is a well respected program and it is recommended by many users. Read about it and download it from
http://www.superantispyware.com/?tag=VUNDO