Updated October 17, 2009 Latest Version of the WUA is now 7.4.7600.226

NOTE: The appearance of and a couple of options of the Windows Update Control Panel window has changed in Vista when the 7.4.7600.226 release of the Windows Update Agent is installed. To see what it looks like, visit MVP Taurarian's web page.

If Automatic Updates or either Windows or Microsoft Update sites can not update the Windows Update Agent successfully, suggest one download the appropriate WUA from the following URLs and save it.

One can tell when this issue occurs when one is repeatedly informed that Windows needs to reboot to update important files or, after visiting Windows | Microsoft Update, one is repeatedly informed that Windows needs to reboot to complete the update or installation of software components.

32 bit versions of Windows [x86]

64 bit versions of Windows [x64]

Itanium-based versions of Windows [ia64]


Close any open browser or programs.
Prior to installation, go to Start > Run > type in [or copy and paste the below into the Open: line]

net stop wuauserv

Click OK or press Enter.
IF the Background Intelligent Transfer service (BITS) has been started it will also have to be stopped.
By Default, BITS is set to Manual.
To stop BITS if it's started, type in the below and then press Enter

net stop bits

Now run the executable, WindowsUpdateAgent30-xXX.exe [XX represents 32 - 64 bit , or Itanium (ia)]

If during the installation a message appears that the Windows Update Agent is already installed, open a Command Prompt and add /wuforce to the command.

EX: If WindowsUpdateAgent30-x86.exe was saved to the Desktop

Start > Run > type in [or copy & paste the below into the Open: line]

cmd
Click OK or press Enter

At the prompt, type in or copy&paste the below pressing Enter after each command

"%userprofile%\Desktop\WindowsUpdateAgent30-x86.exe" /wuforce
exit

Restart the system and try to update now.