By following the steps below you can clear the file search history in Windows 7.
Important:This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For
added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the windows help article below.
3. Delete MRUListEx on the right pane by right-clicking on it and selecting delete.
4. Close registry editor.
Open Windows explorer, test and see if the search results are cleared.
You can opt to permanently disable Windows Most Recently Used lists (MRU) if Group Policy is enabled in your edition of Windows. Group policy editor is available only in Professional, Ultimate and Enterprise edition of Windows 7. You will not have the Local
Group Policy Editor available in the Windows 7 Starter and Home Premium editions.
Open Group Policy Editor:
1. Click start and in the search area type gpedit.msc
2. Now the group policy editor will open. In it go to User Configuration > Administrative Templates>Windows Components>Windows Explorer
3. In the settings panel under Windows Explorer look for Turn off display of recent search entries in the Windows Explorer search box
4. Right click it and select edit.
5. Use not configured or disabled to keep search history enabled.
6. Use Enable to disable the search history.
7. Close the group policy editor.