comptuer problem. need help please

i have a problem with some files that keep running and cant seem to find them or get rid of them.

i ran hijackthis and the problems are these two lines:

O4 - HKLM\..\Run: [fyyrndi] C:\Program Files\Common Files\System\grwwxgp.exe
O4 - HKLM\..\Run: [yvtcxhx] C:\Program Files\Common Files\Microsoft Shared\vnwbekj.exe

spybot dont work, and hijackthis said it fixed it but it didnt. it stays gone until i run any install exe of any kind.

any ideas? i find nothing about this except a ton of people are having the same problem. i have even put in new hard drives in both computers, and it came back on both. when it starts to run you cant run any kind of virus, spyware program. nor can you do the task manager to stop it.