First app slow after logon

After logging on, the first app (ie: start menu or an application)takes 3-5 minutes to start. After this or if not logged in all run quickly.
This occurs in win95 on an NT4 domain. We use lmhosts and hosts files to identify several computers on thenetwork. I’ve tried editing and removing these files. This does not happen on all computers but is spreading. We have up to date virus protection.
Any ideas?