Unable to reinstall 737-800/900

I had to reinstall the 600/700 due to a corrupt gauge. I did install it over the existing files. Everything works just fine after reinstall. Now when I try to switch to the 800 or 900 I get a crash. I tried reinstalling the 800/900 over my existing files but prior to installation I get the message must install 600/700. Not sure what to try next.

Any help appreciated,

Thanks

Update: Found problem, registry problem and fixed with flight one's registry fixer.