Windows 2000 SP4 setup error

I am trying to update an Windows 2000 SP3 system to SP4. The system runs
Microsoft Exchange
I did a net stop iisadmin /y before attempting the install
It gets to the end and then it errors out saying setup encountered an error
In the svpack.log the last entries before the error are

Starting process: C:\WINNT\system32\sp4iis.exe -l
***
Return Code = 1007
***
DoInstallation:RunInfProcesses for ProcessesToRun Failed

I have seen posts to install 313664 before the install of SP4 but that seems
to relate to a different error in the svpack.log
Starting process: C:\WINNT\system32\wzcsetup.exe /i /P
***

In my case it does not error out on the wzcsetup.exe

I get no other errors other than the setup failed.
I can not upgrade to 2003 so that is not an option

Any help on this would be great