The PC seems to be booting normally again. Last night I found a loose cable which might have caused some problems with the start up. I think that the data lead to the CD-RW D: Drive was half in/half out and therefore corrpting comms to that drive. On boot up this was probably sending spurious signals back to the PC.
Last weekend I tried to cut a disk and it was corrupting every CD I tried to write. This weekend the drive was not even showing in Windows Explorer. I took the case of and found the wire dangling even though I had 'checked' that it was all in place earlier in the week. I guess that it was not properly pushed home.
Does the above scenario with regard to spurios signals sound feasible?
DeepC