Why is it that when I Zip some files in Windows and double click on the resulting file, I can still see all the files in their original form?

Since they were compressed, shouldn’t they be illegible?

Or does Windows temporarily unZip them when I’m looking at them?

Update: I think I found the answer.

I double-clicked on one of the images that was compressed, and I got the following message:

Windows cannot complete the extraction. The destination file could not be created.

So I suppose it is extracting/uncompressing the file. In retrospect, that seems like the obvious answer.


Generally speaking, compressed archives keep a file and folder table inside so that when viewing an archive, you can choose what you want to extract. If you try to open one or more files/folders, the compression program will have to uncompress the that data.


You've discovered one of the reasons why zip files are so popular as phish/virus email attachments. Windows has the built in ability to read the contents of a non-password protected zip file just like it was a folder with uncompressed contents.

I shut that function off back when I was running Windows XP.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.