I can't use my MD-11, what can I do? I bought this copy from Best But in 2004, so it is a legal copy I installed the 9.1 upgrade and the latest MS patch for XP, so now what. But a newer version of FS9? totally nuke the HD and totally start over? Nothing is working here.Michael P.

If you're using a NoCD patch, put the original 9.1 version of FS9.exe in place while doing the install. Also, the NoCD patch you're using probably isn't 9.1-rated, so check the version number. PMDG does not condone or support violations of Microsoft's EULA.