Hi and thanks for all your help have manually deleted all maple files and deleted Maple 11 'folder' in the registry this allowed me to run my installation cd and have successfully activated Maple 11. Will keep you posted if this fix causes any problems. By the way PatrickT the registry reviver only detected problems and did not repair them. Is it worth getting it to enhance performance or is it not worth the £25 i have to pay for it?

I uninstalled using the maple 11 uninstaller but it only worked once