I\'ve tried to install Visual C# 2010 Express edition onto my PC, but whenever I try to run it, I get a error message.
Invalid license data. Reinstall
It appears that this has been reported as a bug, but has been closed as "Not Reproducible". One suggestiong from the Microsoft supporter is to redownload and reinstall:
Please try downloading the complete ISO from http://www.microsoft.com/express/Downloads/#2010-All, mount it as virtual drive. Then execute Visual C# setup from the ISO media and select an option to remove the product. Once the Visual C# has been uninstalled, please try installing it again from the ISO media.
It sounds a bit far fetched to me, but you might want to give it a try.
If that does not help you, I would suggest that you either post a new bug report to Microsoft or vote to reopen the existing one (I am not sure if/how this is possible).