I had a similar problem. The game crashed on startup giving a graphics error. I have a nvidia GTX280 card. Both EEAH and EECH crashed on the first few starts. EEAH finally was able to do it's graphics test on the thIrd start. EECH does not do this check but started after a few tries.
After these first few crashes the games finally seem to start OK. Had not been able to play test yet as I have never flown a hele sim and have not got my joystick working yet, or worked out the controls.
I can not give any advice as my problem looks to be fixed after just trying repeated times.
One thing you could try is downloading the "eech-allmods-1.130.exe" mod. It's updates my help. It is a 706MB file. See the top sticky for the link for this file. I am downloading now.
Item 2 on the below link is the above mod update, right click then save as.
http://www.eechcentral.com/wiki/index.php?title=Installation_guide If you work it out please post your solution.
Regards MarkL