Try uninstalling, running the Microsoft Installer Cleanup Tool, then re-installing.
Forgot about installer cleanup.
I fixed it a different way.
First I tried to repair the install, this gave me another error. Something about an invalid drive. Gave me drive letter, but nothing was mapped to it.
Turns out there was a problem in the registry pointing the users' My Music and My Pictures folder to this non-existent mapped drive.
I modified the registry so they were going to the correct paths. Google "adobe reader invalid drive" is where I found which registry keys to modify.
Ran the repair again after that, no errors. Now Adobe reader seems to be working fine, even without admin rights.