Hi I don't have any Office products at all installed except Microsoft Works. I have just bought Office Home and Student and it keeps telling me my product key is invalid. Have I bought the wrong product and do I need windows 2007 previously installed?
You need to determine if you bought and upgrade version or the full retail.
This should be stated on the disc itself.
If its upgrade you will need a previous version installed or the disks.
Where did you buy the software?