On startup, after the Windows screen I have a black screen with 'Choose system to start' and, in brilliance 'Microsoft Windows XP Home Edition'.
Windows then starts with a very large screen and lettering with distorted colours ( as if it was in a strange 'mode').
When I right click screen 'Properties' then 'Parameters' it is impossible to change the screen resolution from 640x480 pixels as it just reverts to the same figure.
PS.Attempts to restore system to previous dates have not had any effect.

The first think I would try would be to reinstall the correct updated drivers for your video card.
It sounds like you may have had a dual boot system and you got rid of one operating system, is that the case?

To Need Karma.
Received email stating that you had replied but no reply appears on AM Help Desk.
Can you re-send please?

Now have the reply,thanks.I am writing this on my laptop.The problem is on my PC,Packard Bell,Windows XP.
Have not had a dual boot system.
However I recently downloaded 'SlimDrivers',a free program for updating drivers.It found 12 drivers to update and asked if I wished to create a restore point,which I did. I commenced the download of the first one(NVIDIA)which I think is the video, but it seemed to 'freeze'half way through the download so I assumed that the download had failed.This must be the cause of the problem.
I have tried without success,in 'SafeMode'to do a restore on SlimDrivers.
Will now see if I can reinstall correct updated drivers for video card unless you have other suggestions.

This time I am writing from my PC!
Re-installed drivers for Video Card and problem solved.
Many thanks for your help.

Sorry for the delay in getting back to this thread, darn job of mine LOL.
I'm glad it all worked out. Cheers!

Hello again Need Karma,
Regret bothering you again but now find that before each Windows startup I still have black screen asking to 'Choose System To Start' with 'Windows XP Home Edition' highlighted.Can you please tell me how to stop this screen appearing?

That's the reason I asked if you had a dual-boot systen previously. That kind of screen sounds like a boot manager, a small program that asks which of several operating systems you'd like to run. If you can get any more details from that screen that would be great, usually boot managers have their name on that screen. I'm assumin it's the Windows Boot Manager. Try reading here:
How to get rid of vista boot manager in windows 7? - Yahoo! Answers

After sending last query found this after 'googling'.
Read REPLIES - John Barnett MPV. This seems to have fixed it. Thanks again.

http://us.generation-nt.com/answer/black-screen-startup-says-select-microsoft-xp-home-editio-help-154359281.html