I have been using Win2K Pro for a number of years- it will install, with all of Office 2K, in under 2 Gig. Data files can be in a different partition.

That being said, I would recommend at least 256 MB of memory, more if you have it. As a general rule, a disk should be no more than 80-90% filled.

Win2K Pro is based on Win NT4.0, but includes the drivers that were always missing when you tried to set up a WinNT system. Very stable, BUT it is also considered obsolete by Microsoft.