system drive full

On my network, I have 500Megs partioned for the system files on drive c: I'm running NT 4.0. I'm also filtering the Internet through MS Proxy and the SurfWatch program. The Internet services are shutting down be cause of lack of space for logging. At one time, I was told that I needed to clean out or change the size of a certain file so that drive c wouldn't use up all of the available space. Can you tell me what I need to change to keep the c: drive from filling up without reparitioning it to a larger size. As of today - I have 1 meg left.HELP - Also does the pagefile.sys have anything to do with this situation. This file is 130 megs and is found in the c drive of the server.
Thanks for any advice or directions for solving this problem.

NTINFANT