The shortcut points to a mojoportal site on the internet or on your local machine?
Are you running mojoPortal on your local machine using IIS?
What version of Windows did you upgrade from?
I'm using Windows 7 everyday for development and it works fine for me, I also upgraded a while back from Vista and don't recall any problems.
You might check the event log on your machine for error messages. There is not much I can do to help not knowing what error is happening.
Note that by default IIS is not installed on "Home" versions of Windows 7. So you may need to install it manually and re-configure the web site.
Hope it helps,