Thanks for the advice. I have looked in Control panel and there appars to be 3 files relating to Office. Microsoft Office Home and Student 2007, Microsoft Office Powerpoint Viewer 2007 (English), Microsoft Office Activation assistant. Do I uninstall all 3 files?
Yes, remove all three. Run a registry cleaner like CCleaner, then restart the system. After restart, install Office 2010. Good luck!