please forgive my ignorance but turned laptop on this morning and found this message
you can attempt to repair this file by starting Windows Setup using the original Setup CD- ROM
Select "r' at the first screen to start repair
So....how do I run the CD??? I've put it in theDVD player connected via USB but what do I do next?As I can't get the screen to 'find' the DVD player?
Basically this message is saying that somehow your windows registry file has become corrupted.
Often I find this is due to a hard drive going bad (bad sectors). You may want to run full hard drive diagnostics before you continue.
Typically you can tell your computer which device to boot from by either pressing F10 or F12 during the bios boot screen, if not, you can enter your Bios with either DEL, F2, or sometimes F10. Within there you should be able to find a setting to arrange which order the PC looks for bootable devices.
On a side note, Windows won't actually "repair" this file by reinstalling Windows, but you can manually repair it yourself. Windows XP stores registry backups in the "System Volume Information" folder along with other restore data, you can take ownership of this folder and give yourself permissions to access it, upon which you will find the directories arranged by dates, pick a folder with a date from a few days before the problem occured and then find the "SNAPSHOT" folder within there, that will contain your windows registry backup.
Simply copy these files to your windows directory to restore them (make sure to overwrite the existing files)
copy default c:\windows\system32\config\default
copy security c:\windows\system32\config\security
copy software c:\windows\system32\config\software
copy system c:\windows\system32\config\system
copy sam c:\windows\system32\config\sam