http://support.microsoft.com/kb/916261
To resolve this problem, follow these steps:
Click Start, click Run, type explorer, and then click OK.
Locate the following folder:
%windir%\inf
Note The %windir% placeholder represents the path of the WINDOWS system folder. Typically, C:\WINDOWS is the path of the WINDOWS system folder.
The inf folder is a hidden folder. To view the inf folder, follow these steps:
On the Tools menu, click Folder Options, and then click the View tab.
In the Advanced settings list, click Show hidden files and folders under Hidden files and folders.
Click Apply, and then click OK.
Double-click the inf folder, right-click au, and then click Install.
Click Browse. Locate and then click the %windir%\ServicePackFiles\i386 folder if the following conditions are true:
You installed Windows XP SP2 from a Windows XP SP2 CD that included SP2 as part of the base installation.
You downloaded and installed Windows XP SP2 from the Microsoft Web site.
Windows XP SP2 was included with the computer.
Note If the ServicePackFiles folder is not present on the computer, you can copy the files from a slipstreamed Windows XP SP2 installation CD.
Click OK to copy the files.
Change the setting on the computer not to display hidden files and folders. To do this, follow these steps:
On the Tools menu, click Folder Options, and then click the View tab.
In the Advanced settings list, click Do not show hidden files and folders under Hidden files and folders.
Click Apply, and then click OK.
Restart the computer.