PMDG will not install

[cubs 2]

Hi all,I have been running fs9 with the PMDG 747-400 and 400F for years. I recently started having problems with the nav display and the CDU. While flying in LNAV VNAV mode, the aircraft would slowly fly off track, would not stay on the magenta line. The CDU was slow to react with the line select buttons. So something was up. I decided to uninstall the 400F first, then the 400. I rebooted the computer and started the reinstall with the 400 first. I went through the steps of validating and everything went well up until I clicked install. I got a pop up saying: unable to install,fs9 not installed. I could not clear the pop up, it would not go away. The only way to get rid of it was to CNTRL ALT DELET and log off. I am also running FSX with the 747 so I'm not completely out.any ideas? thanks for any inputDoug Morlan

[scandinavian13 5,192]

Try the Flight 1 registry repair tool. There's an issue with the registry that is preventing the computer from recognizing that FS9 is installed.

[cubs 2]

Try the Flight 1 registry repair tool. There's an issue with the registry that is preventing the computer from recognizing that FS9 is installed.

that was the problem, thanks so much for your help!

[scandinavian13 5,192]

Glad I could help.