Why are some of my file names in blue font, while most are
It’s a feature!
I’m assuming that you’re referring to the Windows Explorer listing
of files, probably in detail view.
The blue files are compressed.
Let’s talk about what that means, and how you can turn that display
on and off.
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First let’s show what the question is referring to:
This is a partial listing of the files in my “C:\Windows” folder.
You can see that some of the folders are displayed in blue, while
others are shown in the more common black.
In the NTFS file system, files and folders can be marked as
“compressed”. This means that when the file is written to disk it is
compressed to take up less actual disk space. Files added to a folder
marked as compressed are similarly compressed.
Not all files can be compressed, or rather, not all files get
smaller when you compress them. I know that seems backwards, but if a
file is already compressed, then attempting to compress it a second
time can actually make it a little larger instead.
low on space and it’s impractical for me to get more space by other
Many files these days are already compressed. The best examples are
most audio files like mp3 files, most picture files like the jpg files
that come off of your digital camera, and most video files that you
might get from your video camera or shows that you download.
That’s one reason why file compression is typically off by default;
you don’t want to just blindly start compressing everything, because
not everything should be compressed.
Another reason is that compression and decompression when the file
is written or read takes some extra CPU time. These days it’s not
really a lot, but it can add up if the file is accessed a lot.
So what files are good candidates for compression? Archives of
things that aren’t already compressed and that you don’t access a lot are good candidates.
But then again, with the size of hard disks being what they are
theses days, I rarely compress files, as there’s simply no need to add
yet another something to what happens when reading and writing files. I
only compress files when a disk is running low on space and it’s
impractical for me to get more space by other means.
Let’s look at how to adjust that Windows Explorer setting, and then
also how to actually compress files or folders.
In Windows Explorer click on Tools, Folder
Options and then the View Tab. In the
Advanced settings list scroll down until you see Show encrypted
or compressed NTFS files in color:
Make sure that’s checked, or not, as you desire. (In case you’re
wondering, encrypted files display in green when this option is
selected, and compressed files in blue.)
Now, as for compressing files or folders, simply
right-click on the file or folder you want to compress, click
on Properties, click on the Advanced
button, and you should see something like this:
Make sure that “Compress contents to save disk space” is checked as
appropriate and OK your way back out, and Windows will
compress the file or folder.
(Since you might be tempted, I recommend against Windows
built-in file encryption unless you truly understand the ramifications.
In a nutshell, it’s tied to your Windows login, and if you ever lose
that you will lose the files or folders that you’ve
encrypted – permanently. If you need encryption, I recommend a solution