dllhost.exe

I know dllhost.exe resides in the windows/system32 folder, and that the worm version pops up in the windows/system32/wins. My question is why does the bad version appear after a format and reinstall of windows xp?
Does this file or the svchost.exe file in the windows/system32/wins directory have any effect on a DSL internet connection? At present time internet connection last about 10 minutes after an ipconfig /release and /renew.