Need Disk Space

I am set to upgrade our Winnt 4.0 server to Win 2k. The compant that installed the server set it up with a 2gb C drive. I tryed to run the Win 2k set up with the check up grade switch to run a upgrade report. I recievd the error that I did not have enough disk space. I cleaned out all I could and I am still short. What would be my best best to increase the C partition. Would Partition Magic be ok? Please do not tell me to do a clean install as that would not be an option. any sugestions on this would be appreciated