HELP: dumping memory to disk….every 10-15 minutes???

since january 12th…my PC(OS Win XP Pro) is blocking every 10-15 minutes…a blue screen saying: begining dump memory…then…blocked…every 10-15 minutes…i’ve checked anti-viruses…i’ve upgraded all hardware’s drivers…nothing…this thing’s stabil as a machine…
what should i do (hope other then buying a new PC)??