User profiles in Win. workstation NT 4.0

I had a user who complained of his pc being too slow and being unable to open documents in excel and word. I discovered I was able to open the said documents when I’m logged so I created a new profile for him. This took care of the problem and he was able to access the said documents and his pc was now faster. I have also used the same procedure successfully for other uses with the same problem. The problem now is that within a week, the user says the problem is back.What next can I try?