W2K Printing after upg non MS progs wont

We had All NT4 clients, and NT4 servers.
I had a policies and profiles in effect
to limit the amount of changes anyone could make on a system. (No Settings tab, couldnt change screen, etc.)
Now we’ve moved all clients to W2K. All the servers arestill NT4. With the same policies & profiles – all still work well.
BUT
Microsoft apps can print fine, no other
apps can print. I have looked all over, but I am finding no answer to this. Does anyone have any ideas?
Thanks!