Windows is keeping track of which programs you opened recently. It is using two locations to store those information. The first are the 15 most recently opened documents that are stored in the user profile and I already wrote an article on how to disable the recent documents listing in Windows.
There is however another place that stores the most recent documents. This one is located in the Registry and it stores way more information. The Registry key is called OpenSaveMRU and stores a history of files that have been opened in a common dialog box. All information are stored in sub-keys. The * sub-key contains a list of all files while the keys with file extensions contain only information about files with that extension.
The only way that I discovered to remove those information is to clear all sub-keys of this Registry key. There is probably a more elegant way to do this, maybe a hidden Registry setting that disables it but I was not able to discover it yet.
You can open the Windows Registry to take a look at the key. To do that press Windows R, type regedit and hit enter. Now navigate to the key HKEY_CURRENT_USER \Software \Microsoft \Windows \CurrentVersion \Explorer \ComDlg32 and left-click on the key OpenSaveMRU.
The easiest way is to use a Registry file that clears all the sub-keys immediately. I did create and upload the Registry script for you. Just download the registry script and double-click it (or execute it with regedit /s edit.reg). You could also save it and take a look at it before you execute it which is always a good precaution.
It seems that the sub-keys will not be regenerated after a restart.
Related posts:
Disable Recent Documents Listing in WindowsDisable Recent Documents in Word 2007
Prevent Windows Registry from remembering last key viewed
Add Registry Key Bookmarks
Windows Tip: Edit User Registry of other users
seen on another web site:
to clear the list (checked with regedit)
* right click on the Taskbar and pick Properties
* click the Start Menu tab
* click Customize… button
* click the Advanced tab
* uncheck “List my most recently opened documents” and use the Clear List button