If you look on google.com with the right search phrases you find this is not something you cure with copying in a hal.dll.

Example searches. Since I have no full details I can't tell you a real cure. Also since it's work related and not personal I don't work too hard at this. It's something a business needs to get the right staff for.

Read some at http://www.google.com/search?hl=en&safe=off&q=%22WINDOWS+NT+4.0%22+IRQL+0XA&btnG=Search

Bob