How-To Geek

Make Windows Vista Explorer Preview Pane Work for More File Types

Have you ever noticed that many files don’t seem to work in the Preview Pane in Windows Vista’s Explorer?  Until recently the only way to work around this was a painful registry hack… but now there’s a utility that will let you easily add file types to the preview list.

This article is divided up into two sections… if you want to understand how it all works, you can read through the description of the registry hack. If you just want to get right to the utility, skip down to the bottom.

The Painful Manual Registry Hack Method

Scenario: We want to be able to preview reg hack (.reg) files.

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:


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:


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:



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:


This 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.


You can choose either plain-text or media, which will register Windows Media Player to preview the file. This is useful for non-standard files like .mkv that might play fine in Windows Media player with the right plugins, but might not preview. Click the Apply button and you are done.

Download PreviewConfig from [mirror]

Lowell Heddings, better known online as the How-To Geek, spends all his free time bringing you fresh geekery on a daily basis. You can follow him on if you'd like.

  • Published 04/20/08

Comments (17)

  1. J Klassen

    Any word on how to set this up to preview pdf files? I’ve tried almost everything to try to get pdf previews to work…

  2. ph15h

    @ J Klassen

    PDF files are already previewedy by default on mine and I didn’t even download this yet. I think it’s because Adobe Acrobat 8 (or whatever version is most recent) was installed. I don’t know, I’ll download this and see if it changes anything.

  3. The Geek

    I was pretty sure that the latest Acrobat has a preview filter, but I’ll have to install it again to be sure.

  4. GBot

    I’m VERY pro-Vista, but this is one of the many features that it should have had out of the box (there are far too many “should-haves”). Thanks htg!

  5. Damian

    Thanks! I thought it was very odd that Vista didnt do this – so odd I thought it was me…

  6. Jonadab

    This is just a heads-up that the download is 403. Actually, all of the content at seems to have gone away entirely, replaced with a CentOS-branded default-Apache-install info page.

  7. The Geek


    I put a mirror link for the file up there. Hopefully the winhelponline people don’t mind.

  8. ShqTth

    Great program. Vosta is dumb. out of the box jpg was not registered to work in preview pane.

    I am still mad the Picture thumbnail/icons isn’t present like it was is in XP or 2k. And I can’t really understand why microsoft made it so hard for files to be previewed by default and why all these extea steps are needed just to preview files.

    Sure they came out with a great feature (but killed an old one), but why are all the setting for it half baked and not consistant between versions.

    Exelent program though. Now I can finny preview my jpg files without opening them up in full screen. But automatic picture thumbnail view is what I need though.

  9. Okanovic

    This stuff is great, works perfect
    thx for making and sharing it

  10. Pankaj Mehra

    I found that simply repairing Adobe Acrobat Reader 9 installation using Vista control panel did the trick. Check this out:

  11. adam a

    why is ‘other’ not selectable for the most part? i have photoshop and would like to preview my psd’s. is there a way around this so i can select things like photoshop for psd’s and illustrator for ai’s?

  12. entropy1963

    Any ideas how I can preview office 2003 xls & doc in Windows explorer? I am running vista ultimate.

  13. arshit

    frst of all thanks for this wonderful tweak…its really gr8… and all is wrking gr8 for me except the videos(.avi) files i can listen to them via preview pane but there is no video display. (.dat) its neither playing video nor audio…however i can play both the formats in wmp11…i m running vista 64bit home premium…one more question is there is i am unable to view .rar / .zip / .7z…however i guess if we could click on others option given in the utility we will be able to attach our files with the suitable programs like winzip to the compresses file formats…if possible to select plz do tell us how to enable “others” in the utility…n thnx again its really appreciable…

  14. Sanjay Kumar Mishra

    i want to now what is the reason why my computer is running slow

  15. Pete Farmer

    Stephen Taub has written a free program called “Preview Handler Editor” that performs the same function as the (missing-in-action) “PreviewConfig” program. I’m using it with Windows 7 (32-bit), and it works as advertised.

    Stephen Taub, author of the program, describes it in his post at:

    The file itself can be downloaded at:

    Pity that no one seems to have a preview handler for .doc, .xls, and .ppt files!

  16. Dan

    An easier way is just to add the .EXT and then add the PerceivedType as text to view.

  17. Radish

    For text files, you can add the text preview handler to HKEY_CLASSES_ROOT\SystemFileAssociations\text and get everything with PerceivedType=text working in one fell swoop.

    Fell swoops are the best kind of swoop.

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