Back in 1990 when Microsoft released Win 3.0, they claimed it would boot on a 1 MB RAM system, really needed 2 MB to run, and 4 MB to run well. Then came Win 3.1 which needed 2 MB to boot, really needed 4 MB, and took at least 8 MB to do anything useful. With each succeeding release, the RAM requirements kept increasing. I'll attempt to chart to show my point.

Version Claimed minimum RAM to RAM needed to
RAM to boot really run do anything useful
3.0 1 MB 2 MB 4-8 MB
3.1 2 MB 4 MB 8-16 MB
Workgroups 4 MB 8 MB 16-32 MB
95 8 MB 16 MB 32-64 MB
98 16 MB 32 MB 64-128 MB
Me 32 MB 64 MB 128-256 MB
XP 64 MB 128 MB 256-512 MB

Following this trend, it isn't hard to predict that within 5 years or so we'll need 512 MB to boot the newest version of Windows.

Back in 1990 before people began switching to Windows, most people got along fine with an 80286 processor, 1-2 MB of RAM, a 40-80 MB hard drive, and simple EGA or VGA graphics. As soon as we began switching to Windows, we needed multiple megabytes of RAM, a much bigger hard drive, a faster CPU, and better graphics. I've often said that the hardware vendors of the world should line up in a public square and take turns kissing Bill Gate's ass. The various versions of Windows has driven virtually everyone to jump on board the rat race of ever more powerful computers just to get the system to run with the apparant speed of an 80386 running DOS.