My new PC freezes from time to time, all the time

[do0rway]

i got new computer (buy it last week), details from everest:
motherboard: g31 (Motherboard ID 09/05/2008-G31-ICH7-6A89OG05C-00)
what mean the date here on my g31?
memory: 1 GB hynex (Hynix HYMP112U64CP8-S6)
HD: Seagate Barracuda 7200.12 500GB ST3500410AS

when its freeze mostly it realse by it self after 1 mins or so, and while its freeze i can only "alt+ctrl+delete" just to open the taskbar, not to click on something there.
and i can press on the ctrl+esc or the 1 button on the keyboard that do the same.
i can move the mouse, but cant click on nothing.

thats about it, any ideas what goin on? or any software that can run a test on my PC?
thanks guys!!

 

[Route44]

Tell us your power supply make and the amount of wattage. What operating system are you running, video card? How is your sytem airflow?

 

[do0rway]

cidev power supply. p4-500W.
i use WINXP SP3, custom edition.
the video card...mm its on board, could be Intel GMA 3100??? (i found it on everest -> display -> pci / agp video.
what you mean by system airflow? about the fan?
i have 2 fans , 1 of them on the processor.

about my problem look.... for exemple now i wanted to click alt+tab to get to the everest window and its stuck, only when i click alt+esc its release, if i click without the alt+tab , directly on the window i want its ok.
and its keeps freeze when i click alt+tab again and again (just as i write you here i try it again and again)
i dont remember if all the time my PC froze it was when i click alt+tab...but ill try to put attention.

 

[do0rway]

this problem i told you about alt+tab its keep doing it , but only while im in the IE7 and click alt+tab to get to another window (even not ie7 window).
but when im in other windows i can make alt+tab without problem.
maybe its something.....