Can't open 2 windows or programs

[bmd]

Hi,

I'm running XP Pro with a 1800+XP Athlon and 256Mb RAM but I cannot open 2 'Microsoft' windows or programs.

When I open Outlook and I'm in IE, Outlook crashes. When I'm in IE and I open Media Player, Media Player crashes. When I'm in Word and I open Excel, Excel crashes. Basically I cannot have more than 1 'Microsoft product' window (eg, Word, Excel, IE, Outlook, Media Player) open at any one time.

I have uninstalled Norton Systemworks, iMesh, kazaa and have run Ad-Aware but this hasn't helped.

Is there anything I can do short of blanking the disk?

Any help would be greatly appreciated.

Thanks,
Brett