Today I ran into an issue where I had SharePoint 2007 installed on one of my Windows 2008 R2 application servers and I had deleted the SharePoint Central Administration content database without disconnecting it from the farm (using the SharePoint Configuration Wizard).
I tried to disconnect from the farm but each time I ran the configuration wizard, it gave me a security issue saying that it couldn’t access the central admin content database. When I ran the uninstall, it just quit in the midst of uninstall, without any error message or anything.
I then tried to manually clean it up by deleting all the SharePoint web applications and detaching all the SharePoint databases, no dice.
I finally turned off the timer service (net stop sptimerv3) and ran the SharePoint Configuration Wizard and it worked! The wizard gave me a bunch of errors saying that it couldn’t find the central admin database but ended up disconnecting and ended up letting me perform the uninstall.