Windows pdf preview handler - Computers & Internet

The first thing we'll want to do is navigate down to HKEY_CLASSES_ROOT\.reg. Once we are there, we need to check the value of the (Default) key to figure out if there is a ProgID registered, and what the name of it is.

The ProgID is used so that multiple file extensions can have the same settings without duplicating information in the registry. This way the .reg and other keys can point to the "regfile" ProgID to get all their settings


next you'll need to browse down to the ProgID key, where we'll actually apply the hack: HKEY_CLASSES_ROOT\regfile. Once you are there, create a new key called shellex under it, and then create another key under that one with this name:

{8895b1c6-b41f-4c1c-a562-0d564250836f}

This key is the unique ID that tells Windows Explorer you want to set a preview handler. Once you've created that key and selected it, you'll see a new (Default) key on the right hand side which you'll want to modify.

Double-click on the (Default) key, and use the following text for the value:

{1531d583-8375-4d3f-b5fb-d23bbd169f22}

This key is the unique ID for the Windows TXT Preview Handler, which I figured out by looking under the list of currently registered Preview Handlers in the registry:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\PreviewHandlers

You could substitute any one of these preview handlers… if you wanted to register a media file preview handler, you could use {031EE060-67BC-460d-8847-E4A7C5E45A27} as the value instead of using the preview handler for text files.

At this point, you should be able to select a .reg file and see its contents in the Preview pane:

his same method would work for any other file type, but that could get really tedious.

Adding Preview File Types The Easy Way

Now that we know how it all works (or not, as you probably skipped down to this part), you can use the free PreviewConfig utility for Windows Vista, which is just extremely simple to use. Just select the file type on the left, and then select the handler you want for it on the right.