I'd like to be able to examine the contents of a JAR file without having to install Winzip or some other tool and without having to rename the file. Windows Explorer can open ZIP files just fine; is there some registry setting I can use to let it treat JARs like ZIPs?

migrated from stackoverflow.com Mar 18 '10 at 21:01

This question came from our site for professional and enthusiast programmers.

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    i wonder why this was migrated. why would anyone but a programmer be interested in this. – Jeff Martin Mar 22 '10 at 17:45

Or from the command line:

assoc .jar=CompressedFolder

Under Vista (or higher) you have to run this in an elevated Command Prompt.

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    NB: for Vista and above, you'll probably need to run the command prompt with elevated privileges i.e. as Administrator. – Mal Ross May 25 '10 at 12:45
  • works on Windows 8 as well +1. Thanks! – yair Nov 11 '13 at 19:19
  • Also works on Windows 10 in CMD. Does not work in PowerShell. While you're doing this, I suggest you do it with .ear and .war, too. – ArtOfWarfare Mar 3 '16 at 20:25
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    Also, assoc .jar=jarfile to restore – Numeron May 11 '17 at 10:51

I tried exporting HKEY_CLASSES_ROOT\.zip, changing all references of '.zip' to '.jar' and importing it to HKEY_CLASSES_ROOT\.jar.

Under Vista at least it let me open a .jar file as if it were a .zip.


What you need to do is associate the JAR extension in Windows Explorer with Compressed folders. From Windows Explorer select tools / Folder Options. Then the Files Types tab. Select New and associate JAR Compressed (ZIP) Folder.


The HKEY_CLASSES_ROOT trick doesnt work under Windows 7. There mut be some compelling reason that MSFT doesnt want us to do this.

  • Worked fine for me under Windows 7. – Brannon Nov 30 '09 at 4:29

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