sp4iis.exe error when installing Windows 2000 Service Pack 4

[Steve]

When installing Windows 2000 Service Pack 4 I get an error
message involving sp4iis.exe, and then given the option to
uninstall which I do. How do I get SP4 to install? The
relevant part of the log file is below:

***

Starting process: sptsupd.exe
***

Return Code = 0
***

Starting process: C:\WINNT\system32\sp4iis.exe -l
***

Return Code = 3221225477
***

DoInstallation:RunInfProcesses for ProcessesToRun Failed
***

Service Pack 4 Setup encountered an error: An error in
updating your system has occurred.
***

Failed Deleting C:\WINNT\system32\msiinst.tmp 2
***

VerifySize: Unable to verify size: Source = NULL:
c:\winnt\oem19.cat

***

An error in updating your system has occurred.

Select 'OK' to undo the changes that have been made, or
select 'Cancel' to quit. If you select 'Cancel', your
system will be left in a partially updated state and may
not work correctly.
***

Message displayed to the user: An error in updating your
system has occurred.

Select 'OK' to undo the changes that have been made, or
select 'Cancel' to quit. If you select 'Cancel', your
system will be left in a partially updated state and may
not work corr
***

User Input: OK
***

Starting process:
C:\WINNT\$NtServicePackUninstall$\spuninst\spuninst.exe /~
-u
***

Dirty Uninstall was successful

***