I have debated which forum to post this in, but here goes. I tried updating an existing Exchange 2007 single server installation to SP1. The installation went smoothly until well into the Client Access portion. It quit suddenly, apparently while looking for the EWS virtual directory. I'm trying to avoid disruption of service during weekdays while the system is heavily used. While I'm working on thesolution to this error, I have managed to get everything running again including OWA (showing the upgraded interface) except the Exchange POP3 services. When I try to start the POP3 services it fails. Event Viewer shows a .NET Runtime 2.0 error, with a faulting application pop3service.exe. I uninstalled and reinstalled .NET Framework 2.0 to no avail. Any ideas on how I might get the POP3 services running again would be appreciated.