This sounds like a heat problems to me. Do you have good thermal compound
between the processor and the heat sink? Processor fan working?

>>>
>>>  I recently finished my first complete build from the ground
>>>  up.  I am using a ASUS P4R800V-Deluxe motherboard, Pentium 4
>>>  3.0 GHz processor, with a Western Digital 40 GB IDE HDD.  I
>>>  also have a DVD ROM, CD-R/RW and Floppy from my old Gateway
>>>  computer in it.  It's powered by a 450W power supply.  At
>>>  first I ran into some grounding problems with the board
>>>  contacting the case, but resolved those, and have the computer
>>>  booting up and posting fine.  I originally had 2 256 MB PC3200
>>>  DDR RAM from AMPO made from Wintec in the system.  I booted it
>>>  up with the Windows ME startup disk, ran fdisk and format on
>>>  the HDD just fine, I then inserted my Windows XP Update disk
>>>  into the DVD-ROM drive and restarted it, it read the CD, began
>>>  to load the files and when it got to the point when it said
>>>  "starting windows", the computer just shut off without warning.  I trie
>>>  d the same thing with the CD in the CD-R/RW drive and the same
>>>  thing happened.  I then tried it with the jumper on the HDD on
>>>  master, cable select, took the jumper completely off, no
>>>  change.  I downloaded memtest86+ and made a boot disk out of
>>>  it and ran that, and 1 or 2 seconds after the program loaded
>>>  and began running it the computer shut off.  I tried it with
>>>  each ram stick in the DIMM slot individually and it shut off
>>>  sooner than it had with both.  Though, when I start up the
>>>  computer and enter the BIOS it reads the RAM and displays the
>>>  correct amount of memory.  This lead me to believe perhaps the
>>>  RAM was bad.  I then went out today and bought a PNY 512MB
>>>  PC3200 DDR400 RAM and tried that running the memtest86+.  The
>>>  test ran a couple seconds longer than it had with the other
>>>  two sticks, but the computer still shut off.  I tried it in
>>>  each DIMM slot and ran the test for each one and for some
>>>  slots it ran longer than others, but inevitably at some point
>>>  it shut off.  I'm at my wits e
>>>  nd and have no idea what to do, PLEASE HELP ME!!!!!!!!  Thank
>>>  you so much!!!!  -Clay

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