Some programs will think they're out of memory on NT with 2 gigs of total memory (swap + physical) free. Other programs will have the same problem at 4 gigs. Since you have 2 gigs physical and 20 gigs free hard disk, you can easily end up with either 2 or 4 gigs free. My favorites are programs which refuse to install if there's over 2 gigs free hard drive space.