graphics drivers are the main cause of restarts and errors,i use to get recovered from a serious error message all the time untill i installed sp1,i see you have that though.
update windows anyway,may help,critical ones fix security issues,others for bugs etc. click here
get the latest drivers for your graphics card may help too click here and updating your motherboard drivers is a good idea too,get the latest ones from the mothorboard or computer manufacturers website.
have a read click here;en-us;308041 also.