if you hav a good computer start with upgrading you RaM to 1 gig * 2 if your hardcore instancer * its best that you have Cable or higher...... also to not crash underclock your graphics card by a smugde to increase your chance to not crash
http://www.tomshardware.com has guides for overclocking/underclocking graphics cards and CPus, also much more. Hope this helps.
- Lethal