When attempting to install KMS onto a Windows 2003 SP2 x86 server, I received a ‘Setup Error’ when running the command line ‘KMSW2K3.exe /l:c:\kmsinst.log’.

The installation then failed and rolled back without any further explanation.
Even the log file failed to shed any real light on the problem.

Turns out that I had to re-register my WMI components!

The following commands came from this link.

They are;

cd /d %windir%\system32\wbem
for %i in (*.dll) do RegSvr32 -s %i
for %i in (*.exe) do %i /RegServer

Obscure, but may hopefully help someone!