For the most part, many of us are familiar with the various folder icons included with Windows over the years, but once in a while, a new one shows up. With that in mind, today’s SuperUser Q&A post has the answer to a curious reader’s question.

Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites.

The Question

SuperUser reader K.A. wants to know what a Windows folder icon with double blue arrows means:

While browsing through my Windows directory, I found the Panther subdirectory, which had this folder icon:

Does anyone know what this signifies? I was able to open it normally, and it was, to all appearances, a normal directory.

What does a Windows folder icon with double blue arrows mean?

The Answer

SuperUser contributor Biswa has the answer for us:

This means the folder is compressed. You can right-click on the folder and see that the Compress contents to save disk space option is checked.

The Panther folder is created when you first install Windows, or when you run the Media Creation Tool or Update Assistance Tool from Microsoft.

The NTFS file system used by Windows has a built-in compression feature known as NTFS compression. NTFS compression makes files smaller on your hard drive. NTFS compression is ideal for files you rarely access and saving space on small hard drives.

To get started, right-click the file, folder, or hard drive you want to compress/decompress and select Properties. Click the Advanced button under Attributes. Enable/Disable the Compress contents to save disk space option and click OK twice. If you enabled compression for a folder, Windows will also ask you whether or not you want to encrypt subfolders and files.

RELATED: How to Use NTFS Compression and When You Might Want To

Have something to add to the explanation? Sound off in the comments. Want to read more answers from other tech-savvy Stack Exchange users? Check out the full discussion thread here.

Image Credit: Biswa (SuperUser)

Akemi Iwaya
Akemi Iwaya has been part of the How-To Geek/LifeSavvy Media team since 2009. She has previously written under the pen name "Asian Angel" and was a Lifehacker intern before joining How-To Geek/LifeSavvy Media. She has been quoted as an authoritative source by ZDNet Worldwide.
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