My Splunk Installation failed with the error
<< Splunk Installer was unable to start Splunk Services.
Please make sure you have provided the correct username and/or password, and the user you are trying to run Splunk as has the correct privileges. Exitcode='4' >>
After that the installation is rolled back. We double checked the permission and run the installation as local Administrator, still not chances
It is not at all a permission problem as the error suggests. The service fails to start with error " Error 193 oxc1" which is described in: http://support.microsoft.com/default.aspx?scid=kb;en-us;Q325680 .
The problem was caused by the presence of a file called C:Program ; once removed the installation runs like a charm