Error number: 0x80070420

I reinstalled Windows XP Home over my existing XP Home installation, but I
used another XP CD because the one I own was unable to be accessed by my CD
drive. I registered the second installation with my original XP's product key
number. Everything works fine but when I use Windows Update I get this error
[Error number: 0x80070420]

Please help me understand what the problem is. Thanks.

[arcon5]

Try this
go to
Start | Run
type

regsvr32 wuaueng.dll

and click OK - reboot,
If you get any error messages, try the same command while in Safe Mode

Let us know the results.

You receive a "0x80070420" error code when you use the Windows Update
or Microsoft Update Web sites to install updates (25 Sept-08)
http://support.microsoft.com/kb/958054

another 1 year and 3 months later it helped me out :D

[computerman]

I had the same problem and found out how to fix it all you have to do is turn off your firewall and start your windows updates download again and it will download all the new updates have a great day