R in Task Manager causing problems

I'm not sure where this came from, but a user's Windows 98 PC is now real slow especially on boot and it seems busy all the time. When going into Task Manager, I see one or two instances of an item called R. Just the capital letter R. Never seen this before. I can't seem to identify anything in startup or installed programs that might be related to this. I end task on it, and the computer behaves ok, but how can I get rid of it permanently? I don't even know what it is...