https://support.microsoft.com/en-us/kb/2700567

To reset the Windows Update components, follow these steps:

1. Click Start, click Run, type cmd, and then press Enter.
2. At the Command Prompt window that appears, type net stop bits, and then press Enter.
3. Type net stop wuauserv, and then press Enter.
4. Delete the qmgr*.dat files. To do this, type the following command, and then press Enter:
   Del "%ALLUSERSPROFILE%\Application Data\Microsoft\Network\Downloader\qmgr*.dat"
5. Type cd /d %windir%\system32, and then press Enter.
6. To reregister the BITS and Windows Update files, type the following commands, and make sure that you press Enter after you type each command.
   • regsvr32.exe atl.dll
   • regsvr32.exe urlmon.dll
   • regsvr32.exe mshtml.dll
   • regsvr32.exe shdocvw.dll
   • regsvr32.exe browseui.dll
   • regsvr32.exe jscript.dll
   • regsvr32.exe vbscript.dll
   • regsvr32.exe scrrun.dll
   • regsvr32.exe msxml.dll
   • regsvr32.exe msxml3.dll
   • regsvr32.exe msxml6.dll
   • regsvr32.exe actxprxy.dll
   • regsvr32.exe softpub.dll
   • regsvr32.exe wintrust.dll
   • regsvr32.exe dssenh.dll
   • regsvr32.exe rsaenh.dll
   • regsvr32.exe gpkcsp.dll
   • regsvr32.exe sccbase.dll
   • regsvr32.exe slbcsp.dll
   • regsvr32.exe cryptdlg.dll
   • regsvr32.exe oleaut32.dll
   • regsvr32.exe ole32.dll
   • regsvr32.exe shell32.dll
   • regsvr32.exe initpki.dll
   • regsvr32.exe wuapi.dll
   • regsvr32.exe wuaueng.dll
   • regsvr32.exe wuaueng1.dll
   • regsvr32.exe wucltui.dll
   • regsvr32.exe wups.dll
   • regsvr32.exe wups2.dll
   • regsvr32.exe wuweb.dll
   • regsvr32.exe qmgr.dll
   • regsvr32.exe qmgrprxy.dll
   • regsvr32.exe wucltux.dll
   • regsvr32.exe muweb.dll
   • regsvr32.exe wuwebv.dll
7. Reset Winsock. To do this, type netsh reset winsock, and then press Enter.
8. If you are running Windows XP, set the proxy setting. To do this, type proxycfg.exe -d at the command prompt and then press Enter.
9. To restart the BITS and Windows Update services, type the following commands at the command prompt, and make sure that you press Enter after you type each command:
   • net start bits
   • net start wuauserv
10. If you are running Windows Vista or Windows 7, clear the BITS queue. To do this, type bitsadmin.exe /reset /allusers at the command prompt, and then press Enter.
11. Install the latest Windows Update Agent. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
    949104 How to obtain the latest version of the Windows Update Agent to help manage updates on a computer
12. Restart the computer.