I have just installed Server 2008R2 on a test server which all went as normal. However, after doing windows updates, changing the name of the machine and rebooting the local administrator password did not work.
I used a password reset tool to reset this password but now the Administrator account seems to be disassociated in some way from he install. I can change the password properties for the local administrator and log in and log out without any problem but when the system is rebooted any properties set on the Administrator account are lost and do not persist (this includes password, enable etc.)
Any ideas would be much appreciated. This is something I never come across in many 2008R2 installs and has me baffled.