[johnr43]

pc keeps shutting down if i make it work hard .. like games etc .. have replaced ram .. power pack .. but it keeps shutting down any ideas ?

[ComatoseClown]

sounds like the cpu is getting too hot..make sure your heat sink fan is clear of dust and is running properly..also get a meat monitor like Speedfan and see what the temps are...if you cant bring them down with the stock HSF then get an aftermarket one

[Nitestick]

list your pc specs please. run memtest86 to see if your ram is getting errors. if that is the case then that is probably the cause of your shutdowns. but like h4x3r said it is probably overheating. the classic method of testing for overheating is to open up the side panel and have a desktop/pedestal fan blow on the components in your pc. normally if it is overheating it will provide enough airflow to stop the symptoms, thus pointing to overheating as the cause. however if the reboots still occur it is possible that it is something else.