Dell Inspiron 700m laptop powers off randomly

I have a Dell Inspiron laptop which after turning it on, would just shut off. It didn't matter whether or not the power cable was plugged in. So I thought maybe the hard drive is broken and a file is preventing windows from booting. I got an external enclosure and copied all my files over to another computer, so the hdd worked fine. I then tried to reinstall Windwos XP SP3. I boot from CD, deleted the current partitions, created 1 new one and pressed Enter to install Windows. About 6% in, the computer shut off again.

I imagine this isn't a software issue, since the computer had no software and still shut off (which is why I'm posting in the hardware forum).

Now when it boots, it says error loading OS obviously because there is none deleted in the previous step.

If I reboot and boot from CD again, it gets to the point that says Starting Windows (to install it from disc) and then reboots, and I'm back to where I started.

I also tried Diagnostics from the boot menu (under the hard drive and cd-rom) and after 8 passed tests, it shut off during the memory test. Could it be faulty/old/broken RAM?

Does anyone have any ideas on how to fix this or reinstall Windows? What could the problem be?

 

I cleaned out the computer with a can of air and it still shuts off randomly while installing Windows, or during the diagnostic. Do you think it could be because of the internal power thing with the AC adapter plugs into?

 

What you are suggesting does sound remarkably like faulty RAM.

Try this: download and burn memtest 86+ to a CD and leave it to run until it shuts off. See if it generates errors or not before it shuts off.

memtest 86+ can be downloaded here: http://www.memtest.org/

 

How long should the memory test take?

It's been running for a few hours. Where at the top it says

Pass x%
Test x%
Test #x

at about Pass: 40% it says on the bottom of the screen "*****Pass complete, no errors, press Esc to exit*****

Then when it got to Pass 100%, it restarted, and now it's up to Pass: 24%.

How do I know when the test is over?

The good news is, it hasn't shut down since I start the test at around 9:30 am (2 hours ago as of this post).