*WARNING*
6. Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk. Navigate to the following key:HKEY_Local_Machine\Software\Microsoft\WindowsNT\CurrentVersion\SvcHost.
7. Double-click to open the netsvcs key.
8. Under Value Data.
9. Add BITS and WUAUSERV to the list of services.
10. Click OK.
11. Exit the registry.
12. Restart the system.

This 0x8007043b error "fix" has also been found to work in some newsgroup postings.......

Try registering the following:

Click Start, select Run and type (pressing enter after each one and wait for the
success message):

net.exe stop wuauserv

Press Ok

Repeat for the following:

regsvr32 wuapi.dll
regsvr32 wups.dll
regsvr32 wuaueng.dll
regsvr32 wucltui.dll
regsvr32 msxml3.dll
regsvr32 atl.dll

net.exe start wuauserv

I hope you did them separate. They both don't go in the same Value Data box.