Had a laptop to look at over the weekend and it works for around 20mins then shutsdown.

I'm convinced its an over-heating problem.

Now the owner has asked me to get them a laptop cooler - I was thinking of this one http://www.dabs.com/products/akasa-alum ... 4294951204 but am open to other suggestions.

The laptop is an Acer Aspire 5720Z.

Most tests show that they make a negligible difference compared to running the laptop on a firm surface.

The primary thing is to ensure you never block the air-intakes on the laptop. Ironically, these are often underneath so using them on your lap is not a good option.

Far better to service the laptop. It is probably full of fluff, a fan has failed or perhaps something has dislodged.

I bought one for my last laptop and it was useless. The reason? There were no vents on the underside of the laptop that matched the positions of the fans.

What is needed is a cooler where you can reposition the fans so they're not blowing against solid plastic.

A while ago my laptop completely failed, no shutdown, just immediate power-off, after overheating when playing Portal. The dedicated graphics chip (ATI Mobility Radeon HD 2600) tends to get too hot if the laptop is put on the wrong type of surface - and I do mean a hard flat surface here - it was a laptop tray table.

I'm sure in some cases there may be little difference when using a cooler. However, I got http://www.ebuyer.com/product/61069 and have noticed that the temperature recorded by Core Temp has dropped by over 15C using the fans on their high setting (audible), and nearly 10C on low (very quiet). Even the extra height gained under the chassis with no fans on keeps the CPU 5C cooler than before!

The fans in the cooler do not match up to the location of the CPU fan intake, but nevertheless I find that it makes a huge difference to internal temperatures in the fact that the bottom of the laptop chassis, which used to be very hot to the touch, is now kept at around room temperature, if not below. This seems to efficiently take the heat out of the laptop even without passing a stream of cold air into the CPU fan intake.

Thanks for your input - I have gone with the Antec Notebook cooler so we'll see how well it does

Antec cooler arrived and it seemed to do the business as I ran the laptop for 3-4 hours without any issues at all - gave it some stress tests etc.

When I turned laptop off the base was barely warm.

Good call and good result