Page 877 - Windows 10 May 2019 Update The Missing Manual: The Book That Should Have Been in the Box

Note

You can’t encrypt system files or any files in the system root folder (usually the Windows folder).
You can’t encrypt files and folders on FAT32 drives, either.

Finally, note that you can’t both encrypt and compress the same file or folder. You can, however,
encrypt files that have been compressed using another technology, such as .zip files or compressed
image files.

After your files have been encrypted, you may be surprised to see that,
other than their color, nothing seems to have changed. You can open them

the same way you always did, change them, and save them as usual.
Windows is just doing its job: protecting these files with the minimum
inconvenience to you.

Still, if someone with a different account tries to open one of these files, a
message cheerfully informs them that they don’t have the proper
permissions to access the file.

EFS Rules

Any files or folders you move into an EFS-encrypted folder get encrypted,
too. But dragging a file out of one doesn’t unprotect it; it remains encrypted

as long as it’s on an NTFS drive. A protected file loses its encryption only
in these circumstances:

You manually decrypt the file (by turning off the checkbox in the
Properties box).

You move it to a FAT32 or exFAT drive.

You transmit it via a network or email. When you attach the file

to an email or send it across the network, Windows decrypts the
file before sending it on its way.

By the way, even if passing evildoers can’t open your private file, they can
still delete it—unless you’ve protected it using Windows’ permissions
feature (to learn more, see “NTFS Permissions” on this book’s “Missing