Unable to Install Silverlight
I was unable to install Silverlight on a Windows 2003 server, it failed with error 1625.
I took a look in the %TEMP%/SilverlightMSI.log and found this entry:
This installation is forbidden by system policy. Contact your system administrator.
This was strange as we don't have any GPOs to restrict software and UAC wasn't a factor.
A few lines up there was another entry:
Machine policy value 'DisablePatch' is 1.
I opened up Regedit, navigated to HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\WindowsInstaller and changed the 'DisablePatch' value to 0.
Bingo! This time the installation was successful.