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Using Your Computer > Troubleshooting Computer Problems

Computer not starting up properly?

By Lasa Information Systems Team

What to do if you hit the power button and nothing happens or you are greeted by an error message…

Computer not starting up properly?

Note: The following information is given in good faith but Lasa cannot be held responsible for any actions taken which do not resolve the issues. If in doubt get advice from a competent source before proceeding with anything you're unsure of.

Errors can occur on machines running any operating system and the remedies are generally similar but differences in the way PCs boot and show information as they start up occur because of variation in versions of Windows and how manufacturers set PCs up.

The computer doesn't boot up

If your computer is completely dead, first check all of your power connections and check the power switch is on! If the cables seem to already be plugged in, unplug and replug them. If you're using an extension lead, check that is OK.

Make sure your monitor is also firmly plugged in. Try different cables and also check the fuse in the plug. Turn your machine back on. If your computer still does not boot up, try another appliance in the socket to make sure that it's not the electricity supply itself. If it's still not working, then it sounds like a job for your support company.

There are a number of things it could be: the computer's power switch is faulty and may need replacing; the power supply in the computer could be dead and will also require replacement (if it's an old machine it might not however make economic sense to replace the power supply as these can be expensive).

The computer starts but hangs

If your computer stops responding (hangs) during the POST stage (Power On Self Test) or does not find an operating system on a drive to run, then it could be that there is a problem with the hard drive or other hardware. You will need specialist help to resolve this - make sure you document everything carefully so you can advise the support person of the problem.

If you receive an error message, such as a fatal exception error message or an invalid VxD error message (a Vxd file is a virtual device driver) then there's probably a problem with the Windows installation and it's time to hit the Internet and use Google or another search engine to see if anyone else has had the same problem (this assumes you have another machine in the office that can connect to the Internet, though…).

Firstly, write down the error message exactly as it's displayed and use that, or part of it if it's very long, as a search term.

For a Windows 98 machine, check Microsoft's Knowledge Base:;en-us;q188867

For a Windows ME machine;en-us;q273738

For a Windows 2000 machine;hu;315396

For a Windows XP machine;en-us;308041

Keyboard or mouse error on boot up

This commonly happens when your mouse or keyboard cables have been knocked loose. Simply shutdown your machine (don't attempt to replug them in while the PC is on) and unplug and replug both peripherals making sure to plug each one in the correct port - they should be labelled. This should fix the error.

If you still are experiencing the error, press the Num Lock key on your keyboard several times while your machine is on. The Num Lock indicator light should turn on and off. If it does not, the keyboard could need replacing - shut the machine down and try one from another PC in the office if you have one.

If Windows starts up and you still don't have any cursor movement then you could try another mouse. Again be careful to shut the machine down before swapping them over. If this doesn't cure it, then it could be the driver (software for controlling the mouse). Try reinstalling the mouse driver from the disc that came with it - if you don't have the disc then you might have to download it from the manufacturers web site.

Hard disk error

If you receive a message saying that an invalid system disc is present it is probable that a floppy disc has been left in the drive - just remove it and hit any key to restart the boot process.

If the machine stops half way through the POST and does not display any information for the hard drive it could one of several things: If the PC has recently been moved it could be that the cable connecting the drive to the motherboard has come unplugged - if you are feeling confident, open the box up and check the ribbon cable is secure at both ends - you could try pulling it out and reconnecting it.

Also check that the power cable to the drive is in place. If the above doesn't help, then the drive may have died. You will need to call in someone experienced in computer maintenance to replace the drive which will also need to have an operating system (Windows, usually) installed on it, all your applications like Office, Antivirus etc. reloaded and printers and other peripherals set up again.

Suffice it to say, a recent back-up of your files will help you to restore your computer to full health - and remember to keep all those dull looking recovery and driver disks that came with your PC somewhere handy. This is when they come in handy!

If you receive an error message saying that an operating system cannot be found then it could be that the file system on the drive has been damaged in some way, possibly by a virus. A reinstall of the operating system will probably be required but if you can boot the PC by using a floppy boot disk you might be able to correct the file system using the scandisk utility or perhaps with a proprietary repair utility. This could be a warning sign though that larger problems are on their way… If you are on a network…

My computer boots up, but isn't logging on to the network


Make sure that the log on name and password are typed exactly as they should be - check the caps lock isn't on if your password is lower case for example.

If someone else has used your PC recently it could still be displaying their user name. If you are sure the log in name and password were typed in correctly, make sure the computer's network cable is firmly plugged into the network card. If it is, jiggle it or unplug and replug. Try another cable if this doesn't work.

Check it's in the right port and not plugged into a modem socket, for example. Restart your machine. If you are still unable to log on to the network, contact your network administrator - if you have one!

Other useful items and further reading:For general troubleshooting information see the knowledgebase article A Guide to Troubleshooting PC.

About the author

Lasa Information Systems Team
Lasa's Information Systems Team provides a range of services to third sector organisations including ICT Health Checks and consulting on the best application of technology in your organisation. Lasa IST maintains the knowledgebase. Follow us on Twitter @LasaICT


antivirus, Boot, Driver, Hard Disk, Hard Drive, Hardware, Internet, Modem, Monitor, Motherboard, Network, Operating System, Search Engine, Software, Switch, Virus, Web Site

Published: 22nd April 2003 Reviewed: 14th May 2006

Copyright © 2003 Lasa Information Systems Team

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