Right now restart it, probably it wil be just loaded upon the windows startup,so do what bigmac sayd.
check the process list,try with Hijackthis,if you find any strange process / service,
check the reg key / fiile that loads it (can be done trought many ways, msconfig,process explorer, etc),
disable it, go in the directory, remove every files,and reboot.
I suggest you to do the removal steps, in safe mode.