Updates are not installed successfully from Windows Update, from Microsoft Update, or by using Automatic Updates.
Open a command prompt and follow the instuctions:
Method 1: Register the Wups2.dll file in Windows
To register the Wups2.dll file in Windows, follow these steps:
Stop the Automatic Updates service. To do this, follow these steps:
Click Start, click Run, type cmd, and then click OK.
At the command prompt, type the following command, and then press ENTER:
net stop wuauserv
Register the Wups2.dll file. To do this, follow these steps:
At the command prompt, type the following command, and then press ENTER:
regsvr32 %windir%\system32\wups2.dll
Note For a computer that is running Windows XP Professional x64 Edition, type the following command, and then press ENTER:
regsvr32 %windir%\syswow64\wups2.dll
Click OK on each verification message that you receive.
Start the Automatic Updates service. To do this, type the following command at the command prompt, and then press ENTER:
net start wuauserv
Exit the command prompt. To do this type exit, and then press ENTER.
Method 2: Download and install the Windows Update Agent
Here