Error Reinstalling Exchange Server 2007

Error message in spanish:

"     No se puede establecer la propiedad IsProvisionedServer en este objeto porq
ue requiere que la versión del objeto sea 0.1 (8.0.535.0) o posterior. La versió
n actual del objeto es 0.0 (6.5.6500.0)."

As you probably know by now is that you need to prepare AD, the Schema and your Domain (and even prepare legacy permissions) before you can install Exchange Server 2007 on your computer. Well… apparently you need to do this again if you are reinstalling Exchange as it apparently removes part of this upgrades. The big issue here is that once you start your installation you get an error message because you have the wrong version of the schema (or something). Well, let's uninstall… ehm… if Microsoft lets you. Apparently you can't uninstall because setup can't set the property IsProvisionedServer again (but wait, that's why you couldn't install to begin with). Alright, let's upgrade the schema and everything and pray it works this time (you just wished it was that easy). Seeing that you already have started the installation process you can't upgrade, but, wait, you can't roll back yet you need to do this to be able to…. Smells like something makes too much sense here.

Alright, what I did was export and then delete the following folder in the registry:

'HKEY_LOCAL_MACHINESOFTWAREMicrosoftExchange'  

After doing that you can fool setup.com to upgrade the schema and what not. I restored the registry once I was done upgrading A/D and proceeded to uninstall everything from Exchange. Funny thing, that didn't work as well. Setup things you have finished the installation but now it can't find settings as it didn't get that far last time. So nevermind having the above registry folder on the registry and just delete it again (but always back up your registry in case you mess up and be careful). Go to your Exchange 2003 or whatever and remove the Administrative Group. Read this article http://blog.netnerds.net/2006/04/move-an-exchange-server-to-another-administrative-group-using-adsiedit/ and remove the Administrative Group using adsiedit as well if you need to. Try to uninstall again and good luck : )

My final piece of information is that once you remove Exchange 2007 from your box you should not attempt to install it again. I had issues with some web extensions not being removed among other things. I would strongly suggest wiping your box and starting from cero otherwise you might run into other unforseen issues.