POWRPROS.DLL belongs to what app?

I’ve asked to fix some problems in my customer’s network. Howerver, their EDP officers are a bunch of inexperience guys. Therefore, they can’t help me at all. My problem is this file called POWRPROS.DLL keep having loading error in the whole network computers during startup. All the computers are fresh Win98 comp except the server is a NT4.0. I don’t see any unusual app in the server except some anti-virus and HDD mirroring app. How do i solve this error loading error and how do i find out what app this dll belongs to?