RAM trouble

Hi there,

This is quite a complicated thread, but here it goes...

For safety reasons, I have 2 pc's. One desktop for job-related issues, and one laptop for other stuff. The desktop is not connected to the internet to keep it clean.
However. Some programs require more up to date versions of Windows, so I've allready been forced 2 times to connect it anyway. Not a very funny experience, with al the spyware and stuff going on on the net these days...

Point is, the desktop has 1024 DDR RAM, but even with no programs running ( except windows xp pro ) I only have 634 DDR RAM left.

I tried "ctrl-alt-del" to activate the taskmanager, and check the processes tab. But it appears that "the feature was turned of by the administrator" wich is me, but I never did that...

I know there is a program available called pc booster, that can free ram, but I'm a bit reluctant to drag my desktop to an internet connection again in order to register and get the full version. I've got the trial-version, that's how I know how much RAM is being used.

Is there another way of finding out where all that RAM memory is being used?

Is there a way of turning the taskmanager back on?

Little side question: Is it possible that, in this case, my laptop auto-resets as a result of running out of RAM memory?
It's just that when I use Skype ( 2.0 ) my laptop goes dead. Only skype is running, but after a maximum of 5 seconds in the conversation, it goes down. My laptop only has 512 DDR RAM. The skype site itself isn't very helpfull on the subject, that's whay I'm asking here...

Thanks a lot, and sorry for the longish thread,

Gibrril