I installed Visual Studio 2012 Professional. The installation did not complete successfully so I ran a Repair. During the Repair, the following error occurred:

The event log file is full

 

Thanks to a StackOverflow post, (which I'm not finding today), the following steps resolved the issue:

1. In Control Panel, uninstall Visual Studio 2012.

2. Delete all the files in %ProgramData%\Package Cache. To open this folder, open the Run window, and type: %ProgramData%\Package Cache. On Windows 8, the ProgramData folder is hidden.

3. Forcibly remove Visual Studio 2012:

a) Open the command window as Administrator.

b) Type:"drive:\\InstallPath\vs_professional.exe" /uninstall /force

c) Hit Enter.

 

4. Ran the Visual Studio setup again. Success.

 

This article lists the /force option:

How to uninstall Visual Studio 2012
http://support.microsoft.com/kb/2771441/en-us#Force

 

Thanks!