when i try to update to the latest version it downloads and installs to about step 262 from 371 then says completed but hasnt completed at all because i get update message several times a week at startup from prepared 4.5 .
That's not a problem. You'll only see all steps completed if you have ALL FSDT products installed. If the updater says "Complete" and the end, it's because it's completed.
when i after that startup p3d4.5 and start to custumize airport jetways couatle crashes/hangs leaving me no other choice than to restart sim and gsx again resulting in the same problem when customizing again. before this update i never had big problems. maybe u can tell me whats wrong with this update.
There's nothing wrong with the update, and that problem doesn't happen. But of course, it's not possible to help you without any details. When you see "Couatl crashes", do you mean it just crashes, or it gives you the option to open the error details ? If yes, please post your error log.