Hi there my name is XXXXX XXXXX X will be helping you with your question today.
This error often occurs sometimes if you are using another trial key and have already completed a office pro trial. Microsoft will not allow you to use another trial key to install again for another trial length.
If you own the entire MS 2010 Office Pro software and have a key for the full version, then the prior installation may not have been installed correctly and I can give you further instructions on how to clean your previous uninstall.
Please let me know if you are trying to reinstall a trial period, or if you have purchased a retail license key
Chain of events are as follows:
1. Tried to install changes to Ourlook 2010 pro. Asked for Key Code which I could not fine.
2. Purchased Office Home and Business and downloaded. OK.
3. Found Outlook 2010 Pro Key Code and tried to install. Then all the problems started. Cannot uninstall