This is the most worrying sign from a laptop - a claking, or loud whirring sound from the laptop hard disk drive. Usually, a whirring hard disk drive means that the drive is starting to falter or fail. You should immediately back up all your important data! I once heard such noises from the laptop hard drive and within 2 days, the disk had crashed. And this tell tale sign of hard drive failure is usually spot on - so please watch out for this one.

Is your laptop about to give way?

Usually, if you have dead pixels (unlit pixels) in the laptop screen, you can return them to the manufacturer to get a replacement laptop. This depends on the manufacturer's policy though - some of them only replace the laptop if you have more than say, 9 dead pixels across the whole screen. If you suddenly see several dead pixels in the laptop screen, it usually points towards LCD monitor damage, so watch out for this.

This one is pretty common. Usually I hear of folks' whose laptops were fine initially but later starting booting up very, very slowly (10 minutes or more). The number one culprit in such situations is a lot of startup bloatware. Make sure you uninstall any software you don't need (excessive firewall or anti-virus programs cause a huge delay in startup times). If you've done that and the boot up is still slow, you might want to re-install the operating system. Many laptops come with a recovery disk to make this an easy job (just make you back up your critical data and documents first).

Yet another common problem is a battery that runs out of juice within 10 minutes, even though it is fully charged. The problem here, fortunately, is usually with the battery unit and not the laptop itself. So in these circumstances, get yourself a new battery. In certain cases, it could be due to faulty circuitry in the laptop body, though this is rare.

If you have a trackpad that is suddenly responding sluggishly, then it is also a sign that you need your laptop navigation system replaced. Usually, if you use an external mouse, this might not be a problem, but many folks I know use the trackpad and it is immensely irritating if the trackpad fails. So watch out for this sign of laptop failure (and bring an external mouse just in case).

Laptop memory modules are also prone to failure. When you boot the laptop up, try to check the amount of memory (RAM) available in the machine. If you know your laptop has 2GB of RAM, then the boot up screen or BIOS should show 2GB of RAM. If it shows less, it means you have a faulty memory module - which slows down your system immensely.

The other way to check your laptop memory is to go to the Computer icon (in Windows Vista) and click on it. Next, click Help followed by About Windows. The amount of memory available to Windows should be displayed in the dialog box that pops up - make sure it tallies with your understanding of how much RAM you have.