I have tried to add sceneries but I have so many I don't know how or what to add because no matter what way I do it, I get a corrupted EHAM
That's not a problem of the scenery, it's a problem of your video driver settings. There was a similar report here, which was solved by setting the XP compatibility flag.
http://www.fsdreamteam.com/forum/index.php/topic,2921.0.htmlEDIT <<<< I got rid of the FSDT installer and uninstalled the scenery and put back the old Cloud9 Amsterdam and all is ok. I cannot use the EHAM FSDT installer (for the Cloud9 EHAM) as it is causing too many problems. Don't ask why. I've had enough troubleshooting and both FSX and FS9 are back to normal.
NEVER, EVER use the Cloud9 installer. Nothing will work if you do it, and surely nothing from FSDT. Uninstall the Cloud9 EHAM, and reinstall ONLY using FSDT installers. Just to be sure, install the Stand-Alone Addon Manager for FS9 AFTER all the sceneries, so it's sure you have everything updated.
Your problem doesn't have anything to do with the FSDT installer, your problem is a video driver problem and should be fixed as explained above.