Blue File labels?

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mrtricks(Posted 2005) [#1]
A couple of months ago I noticed some of my file labels are blue instead of black. I can't find anything in the help files about it and just wondered why. The files themselves are fine.


VP(Posted 2005) [#2]
Blue = compressed or encrypted.

if you have marked your 'My documents' folder as private, any files you save there will be encrypted and only accessible from your login.

Compressed files also show up as blue for some reason. Windows likes to compress uninstallation scripts for stuff downloaded from Windows Update (look in C:\WINDOWS and see all the $NtUninstallKB873333$ folders, they will all be blue).

You can tell if it's a compressed file if you click on its properties. It will show a file size generally a fair bit higher than the 'size on disk' size.


xlsior(Posted 2005) [#3]
As Vinylpusher mentioned, they are compressed or encrypted files. Windows NT/2000/XP have a built-in compression driver, that can automatically compress/decompress files when you write or read them, in order to conserve diskspace. This is pretty much transparent to the average user.

The advantage: smaller files = more usable diskspace
The disadvantage: your computer needs to do more work (compress/decompress) the files in the background, meaning that these compressed files are slower to handle than uncompressed files.

If you right-click -> Properties on these blue files, you can see both the 'real' size (the amount of data that the file contains) and the size on disk, which is how much diskspace the actually file takes up after it was compressed.

The windows disk cleanup utility which can kick in if you're very low on space can start compressing files that aren't changed very often, which could explain how they started to appear in blue all of a sudden.

3rd party system optimization programs can do this as well for you.

Now, as mentioned above it's also possible that the files are encrypted.. This can be good if you want to protect your data from unauthorized access, other users on your computer won't be able to read the contents of the file in question if they happen to come across them. If you put the harddrive in a different computer, it won't be able to read the file either.
Secure, but also a potential major headache if your operating system dies on you and you try to recover your data -- you won't be able to access it without the embedded security key in your XP profile, which you need to remember to export to a safe location to regain access to those files again when doing disaster-recovery...

so if you're using the encryption deal: just be careful, and make sure you back up the key as well... but most likely you'll find that you simply have compressed files on your computer, and not encrypted ones.


mrtricks(Posted 2005) [#4]
Ah... I did Disk Cleanup a little while ago. That would explain it. Thanks!


GW(Posted 2005) [#5]
some corrections.
Blue file labels denote compression.
Green file labels are for encryption.
also the overhead of de-compression is next to nothing. in some cases it 0% overhead.


xlsior(Posted 2005) [#6]
also the overhead of de-compression is next to nothing


There is overhead for compressing them though, so if you have a file that changes frequently having them in a compressed state can lead to noticable delays


Kanati(Posted 2005) [#7]
With the size of hard drives these days... it's just not worth it.


regaa(Posted 2005) [#8]
..well i had only 4 GB free of 130GB on one partition , after compressing all stuff on this partition i had more than 40GB free. This isn't worth it?