>At 5:00 every night a program runs on the Server that processes through most of the tables and does a LOT of processing.
>
>What affect does it have depending on the amount of users using the application at that time? How will the speed decrease on the NT server and the users workstations? and if you can answer the previous questions, why does the speed decrease?

In addition to testing your own situation, if there is any possible problem, I would schedule the processing to run at the least "in-use" time, and 5 PM doesn't sound good, but don't know your user-schedule. IOW, either automate the processing to 2 AM or so, or as I often do, I have a 6 AM early-bird worker run the processing if it needs manual intervention.

I have not only had many users dumped from my main server, and completely brought down my own server, but also brought down the entire 3rd floor hub system and all the other servers on it, from my heavy-duty processing at busy hours. Everyone was outraged, and I had to make some adjustments to get out of the doghouse. That's your worst case scenario...