You might have your sysadmin look at what they are doing with log & stat files when you start up CATIA. We have a script that copies them to an AIX server, and we found that as that directory became more full, it took longer for Windows to mount it. We now empty that log file directory every night (move them somewhere else).
Another thing to look at is to empty your own log directory. CATIA doesn't do a very good job cleaning this up, so it also gets very full. Again, when our script copies out the log & stat files to the server, as this directory gets larger, CATIA startup times slow down.