Update Rollup 7 for Exchange Server 2007 Service Pack 1 Can Kill OWA and Web Based Services

No matter how careful you are with your network, you cannot avoid getting bitten by patches or fixes occasionally. I have seen this exact same behavior with three different networks, so I think there's some sort of pattern going on. 

Here's what's been happening: Right after you install "Update Rollup 7 for Exchange Server 2007 Service Pack 1" successfully in your environment, OWA and ActiveSync may not work at all. I want to repeat this one more time: the installation might run without any errors or warnings, but you may still end up with a non-functional OWA. 

Uninstalling Rollup 7 might solve the problem, but I have found a better solution: Simply repeat the installation of the "Update Rollup 7 for Exchange Server 2007 Service Pack 1" package one more time. This second install will take care of OWA and Web Based Services problems for good. Only in one instance, the installation process failed to re-enable the Exchange services at the end of the installation. Simply re-enabling Exchange Services and restarting the server solved the problem.

I am not sure under what circumstances this issue occurs, but I hope this simple yet effective tip can save you from frustration.