Right now, my Windows 2000 Pro system is using 116652K out of a total of 471780K (I actually only have 192 MB of RAM). On bootup, it uses about 70MB or so, but I can't remember exactly, since I haven't rebooted it in several days, and it's been almost a month since I even bothered to check the task manager right after booting
Anyway, I currently running Outlook XP, IE, Windows Media Player 7.1, Distributed.net client, MSN Messenger, and ZoneAlarm 2.6.