Hi All, I'm wondering if anyone can help me.
I have a Probook I bought second hand. When I went to buy it, I started it up, checked inside the bottom cover ect....
Did the usual checks and it looked fine.
Got it home and after 20 - 30 min of running, it switches off.
Now it does this on battery and charger. I've ran it without the battery and that didn't make a difference.
Also, it doesn't matter what I'm doing on it, it's always the same amount of time.
I thought CPU over heating but it seems to be blowing air out of the side vents no problem. The fan starts and switches off so it could be a problem with that but I thought I'd ask here first.
Anyone any ideas?

Does it bluescreen or just switch off?

Is it shutting down or restarting?

What version of windows does it have and have you formatted/installed your own version?

It just switches off like all power has been cut to it. Straight away I can switch it back on and it will go for another 20 - 30 min.
It's running Windows 7. I have not formatted it but I have a feeling it has been as it was totally clean when I got it.
It has a windows 7 sticker on the front so it is made to run this OS.

The sticker doesn't indicate that, it just means it came with that OS.

If there's no sound coming from the hard drive (clicking or squeaking) and it's not hot enough to almost-burn your bare hand on the base, I'd put money on it being a power problem. Take it to somewhere (not pcworld) and ask them to check.

In the meantime you can always try using a different power cable or replacing the fuse in the one you're using atm.

To check your temps .. Run this app .. Download latest Version top right http://www.filehippo.com/download_speccy/ Then click on summary .. You can see all hardware temps .. It may help you?

If the BIOS has been restored to Defaults then the default temp settings could be too low.

Win 7
does have power settings Search for "Power Options"
when that screen opens make sure its not set to super duper eco saver settings.

For it to be aprox 20mins this means there is a timer running,
or its getting that hot with in the 20 mins. But if you can restart and then it will run for another 20mins it makes me think its not Temprature related and more of a power setting.

But. . . . i,m not aware of any software program or settings that will shut down the pc as in the power has been cut.

Check the Bios
there may be thermal settings in there, look for a 20min setting or increase the thermal tempratures a little to see if your cut out time increases or not.

Failing the above it sounds like a component could be failing.