I find that with the updates and some office software I see mem usage of 390 MB before running any programs (windows at rest running antivirus) the worlds changing the more MEM the better, windows XP need 1 GB min I upgraded to 3 GB on XP, windows 7 didn't do well for me with 2 GB, 4 GB works much better I went for 8 GB in my machines using the 64 bit OS. I guess it depends on what your office need all our machines got a 1 GB upgrade for normal work server are getting 8 GB