Thank for the responces to my inability to install a Western Digital 80Gb SE. I`m sure now the problem was incompatible ribbon as the correct length for a tower case was`t included with the motherboard. A lead from a local shop was then subsequently replaced. One of the symptons was that I couldn`t install software, though obviously Windows XP installed OK.
I swopped to a 40Gb Maxtor 2Gb cache, and Windows had no problems here. However, if it`s fairly straightforward, I`d like to add another 40Gb Maxtor. As Windows XP is now installed would it just be basically a simple plug-in and go? If any problems could occur I`d leave it as it is.