Have upgraded to vista operating system but it doesn't recognise my hp scanjet 7400c scanner. Have downloaded driver update from the hp web site which is supposed to allow basic functions to work but no joy. Does anyone have a solution as it seems a real shame to have to ditch a perfectly good scanner.

Have you tried e-mailing HP support (they offer life of product e-mail and IM support) to see what is going on. But if the drivers won't work, then yes, you will have to replace the scanner.

Yes had contacted both hp and Microsoft neither were any help. Have though found downloadable software called "vuescan" from VueScan Scanning Software. You can get a trial version to check that it works then pay for the full download - cheaper than a comparable replacement scanner. This info may be helpful to anyone else with a similar problem.