Had success with this.
I re-registered the Windows update dll as suggested by the following
post from
http://forums.vnunet.com/message.jspa?messageID=870658
Try re-registering the windows update components. This may help fix a
corrupt installer
1. Click on Start and Run,
2. Type "REGSVR32 WUAPI.DLL" (without quotation marks) and press
Enter.
3. Should get the message "DllRegisterServer in WUAPI.DLL succeeded"
Click OK.
4. Repeat above for each of the following:
REGSVR32 WUAUENG1.DLL
REGSVR32 ATL.DLL
REGSVR32 WUPS2.DLL
REGSVR32 WUCLTUI.DLL
REGSVR32 WUPS.DLL
REGSVR32 WUWEB.DLL
REGSVR32 WUAUENG.DLL
5. Reboot
Now try to install your updates.
http://forums.vnunet.com/message.jspa?messageID=870658