hi, i put together my pc a while ago so it's not the newest the best but works for me. components are: -p4 mobo from pcchips M950 -p4 2.53 Ghz 533MHz fsb -two 1GB sticks of memory by patriot -120 GB Seagate ultra ata/100 -160 GB seagate ultra ata/100 -DVD burner from Sony -DVD reader from samsung -Radeon x700 pro AGP -floppy -pci wifi -pci fire wire -cpu fan -system fan so how many watts should my ps have, because right now i have 300 watt power supply and my computer started to shut down randomly, it's not like the computer suddenly goes blank, windows xp shuts down like as if i was shutting it down but with out my intervention. this happens when when i'm just browsing internet and listening to music, it's not like i'm using all the resources like when playing games. also my 160GB hdd has only like 10GB free but system hdd which is 120GB has 80GB free. HELP please!!