One of our user here in the company encountered this kind of error, it appeared after she had clicked on Internet Explorer, what is the error all about? Here is the information:
A file that is required to run Search Companion cannot be found. You may need to run Setup.
This behavior can occur if a file required to run Search Companion is missing or damaged. Note that this problem affects only the English-language version of Windows XP.
1. Install Windows XP SP1
2. Download and Install The Hotfix
3. Reinstall The Search Companion
a. Log on to the computer by using an account with administrator permissions.
b. Click Start, click Run, type %systemroot%\inf, and then click OK.
c. Locate the Srchasst.inf file.
d. Right-click the Srchasst.inf file, and then click Install. This reinstalls the files that Search Companion uses.
For more info, please visit this site http://support.microsoft.com/kb/319949