When you press Start > Search on your Windows XP computer, you receive an error:
After you receive this error message, you cannot use Search Companion to search for files or folders, or to search the Internet. The options to search for files or folders, or to search the Internet, are unavailable.This behavior can occur if a file required to run Search Companion is missing or damaged.
Log on to the computer by using an account with administrator permissions.
2. Locate the srchasst.inf file
3. Right-click the Srchasst.inf file and press Install.
4. If you are prompted for the location of msgr3en.dll .You'll need your XP CD or, if you have Service pack installed then extract the files from the Windows\ServicePackFiles\i386 folder.Type C:\Windows\i386 into the Copy Files From dialog and press OK.
Also check: http://support.microsoft.com/kb/319949