I noobed it up and forgot to ad prep before installing exchange 2010. will I have to uninstall and reinstall exchange 2010 after ad prep?

Nope. If you have the permissions, all the prep stuff was run automatically when you ran the install. I assume you are referring to the Exchange prep steps here. You can check the Exchange Setup Logs to verify. If you have a multi-domain environment, you would want to run the commands separately, otherwise, simply running setup is perfectly acceptable.

Also verify the mailflow and do a ExBPA health checkJonas Andersson MCTS: Microsoft Exchange Server 2007/2010 | MCITP: EMA 2007/2010 | MCSE/MCSA Blog: http://www.testlabs.se/blog