After many months of searching, the solution, or at least one that works for me was found in another forum.
Since installing WinXp service pack 2, I received the error message indicating files were missing required to load the search companion (dog). This prevented the search interface from loading.
This is a screenshot illustrating my problem. My desktop is showing through where the search fields should be.
To revert the search interface to an earlier version (without the animated companion icon), add a new key to the registry. The search interface will then load and appear as it did in prior versions of Windows. Who needs the animated companion icon anyway, right?
Open the registry editor by going to: Start>Run and type regedit and click OK. AS ALWAYS, YOU SHOULD MAKE A BACKUP OF THE REGISTRY BEFORE MAKING ANY CHANGES. For instruction on backing up the registry, go to http://support.microsoft.com/kb/322756#2
Then Navigate to: HKEY_CURRENT_USER\Software\Microsoft\Windows\Curre ntVersion\Explorer\CabinetState folder.
Go to: Edit>New>String Value.
Right-click the newly created key and rename it to "use search asst" without quotation marks. Click OK.
Double-click the new "use search asst" key and type "no" in the Value data field. Do not use quotation marks.
Close the registry editor.
This is a screenshot showing the subkey named "use search asst" and its value of "no".
Now when you go to: Start>Search the search interface should load and look like the one shown below.
I hope this helps those of you that have lost the ability to search files and folders on your computer after installing WinXp service pack 2.