Thanks for responding quickly.
Yes, I waited 10 minutes because I used a timer to ensure, and no, I don't have the Windows disc as it is at home and I at work.
Since writing this, I found out my partner was able to get Windows started again but has indicated we may have lost some drivers (he's a little more techy than I am obviously). Thus, we should be able to start the computer this evening at which time we will back everything onto our external hard drive.
My partner plans to do a reformatting of the hard drive on the weekend which will be a lenghty process as he will do this on a regular basis to ensure the longevity of the HD.
Admittedly, our CPU is old (over 4 years) and is probably due for a replacement. If we need to replace it, I hope we can find a CPU which is not VISTA based as we have a number of hardware/software items which will not be compatible with that operating system.
Best,
Darrin