If you open certain types of files in more than one application, you probably use the Open With command. To do so, right-click a file, and select Open With from the resulting shortcut menu. This displays a secondary menu listing the programs that can open this type of file.

In most cases, the Open With list presents only those programs that you'll want to use. But if the list contains programs that you never want to use, you can remove them with a simple registry edit.

Follow these steps:

1. Launch the Registry Editor (Regedit.exe).

2. Navigate to HKEY_CURRENT_USER\Software\Microsoft\Windows\ CurrentVersion\Explorer\FileExts.

3. Double-click the key associated with the file extension of the file type whose Open With list you want to modify.

4. When that key opens, double-click the OpenWithList key.

5. Delete the value associated with the program that you want to remove from the list.

NOTE: Editing the registry is risky, so be sure you have a verified backup before making any changes.