Thanks for the responses. Just to be clear, is it the case that it is not possible on a Windows machine to back up all settings, apps and data on an external HD and then restore them if the computer needs a full reset and windows reinstalling, whereas you can on a Mac if the equivalent is needed?
My crash destroyed all the restore points and my backup was just the data. I am having to reinstall all my programmes from disc or by downloading again. The real problem is that my e-mail was Windows Live Mail, no longer available. While I have all the e-mails and email folders backed up and have a contacts folder, I am having difficulty working out how to migrate these into Outlook or Windows Mail, neither of which I know how to use. My internet provider does have an e-mail system, but I cannot import my contacts and it does not have a record of e-mails sent for Live Mail.
Life seems to have been simpler with pencil, paper, snail mail and Fuji Velvia.