W2K & NAV 2000 – Not enough hard disk?

I’m running Windows 2000 Professional with SP1 and have NAV 2000 loaded. Everytime I try to run NAV I get the error message “Not enough hard disk space to run program.” I tried all the proposed fixes from the Symantec website and still no solution. Currently, my hard disk drive is partitioned with 2GB for the OS, 8GB for the applications, and 10GB for everything else. Anyone have any solutions?