I tried Windows 2000 on an old Pentium 200 with 64 MB of Ram and it was painfully slow, Debian runs fine on that setup. I ran Windows XP on a P2 333 with 128 MB Ram, it works but it's slow. Debian ran very good on that setup.
In linux it all depends on whatever Window Manager and similiar stuff you're running, on the computer with 64 MB Ram Window Maker was very nice, and on the P2 I used Gnome/SawFish.
But yes, some Linux dists. like Red Hat feels as bloated as Windows, well not really but almost. With Linux and a 2GB install you atleast get a few webbrowser, complete dev system and similiar but in Windows you get one crappy Web Browser, a crappy paint program, a crappy Media Player and not much more worth mentioning.