While fixing a virus infected PC today I came across the following Windows Update error in XP 0x80070424.

The PC would not update. I found that Error 0×80070424 is caused by a dll registration problem.

[SOLUTION] to Error number: 0×80070424 in XP Windows Update follow the steps below:

Click on Start -> Run and paste the command below and enter

%SYSTEMROOT%\SYSTEM32\REGSVR32.EXE %SYSTEMROOT%\SYSTEM32\WUAUENG.DLL

Done!

Launch windows update again, you should be able to perform the update now.