We all share a pc at work and recently this pop up has been occuring Ive googled the whole name Trojan-Keylogger.Win32.fung but Im as wearing as the sites that pop up about that as i am about the pop up itself... Any advice?

Reformat. Change any passwords for sites you have accessed at work. (but do it from home )

Try running spybot search and destroy before you go to the format route

im with midnight.

tried that search and destroy - not made any difference - Ive also tried AVG (free version) and aslo Windows defender. I thought shitty pop ups only appeared when on line but even with the router disconected the same one keeps on coming back

If I do have to do a fresh install will i be able to keep all the word documents and such on a HD without problem ?

Or if anyone knows of a resonably priced anti virus thing that will shift it without need for a reformat

AVG is as good as any, and Search & Destroy should find it. Just move the files to another partition or usb stick or something and then format the pc.

IMO ESet NOD32 is the best anti virus by quite a margin, thats assuming you have a virus and not some spyware, you could also try adaware. Or even the version of nod32 with spyware built in.