Ok im quite new to vista and i have the business version on my new laptop from uni, it was brought for me cause im special

Its a toshiba satellite pro and its OK.
2 gig ram, duo core running at 2.26 each and onbroad graphics (ew i know).
Anyway it came with SO much crap running from start up i disabled pretty much everything, including that aero crap!
But half my ram is still being take up and 25% of the CPU!
And the problem i have now since i disabled most things whenever i run word( which is what i want the pc for really) it crashes all the time! Its so annoying!
Any tips other than sticking XP on here? Problem is there is a lot of specialist software on here and its all paid for and i dont wanna stick a dodgy version of XP over a proper version of vista!