Using Compression and Encryption
You can expand a file or folder by completing these steps:
1. In Windows Explorer, right-click the file or folder that you want to expand and
then select Properties.
2. On the General tab of the related property dialog box, click Advanced.
3. In the Advanced Attributes dialog box, clear the “Compress contents to save
disk space” checkbox and click OK twice.
4. For a file, Windows Vista removes compression and expands the file. For a
folder, Windows Vista expands all the files within the folder. If the folder con-
tains subfolders, Windows Vista displays the Confirm Attribute Changes dialog
box, shown in Figure 19-19:
• To expand only the folder and the files it contains, select “Apply changes to
this folder only” and then click OK.
• To expand the folder, subfolders, and all related files, select “Apply changes
to this folder, subfolders and files” and then click OK.
Encrypting Files and Folders
You can use encryption to protect your files and folders so that only you can access
them regardless of the NTFS permissions assigned to those files or folders. The first
time you encrypt a file or folder, Windows Vista creates a personal certificate contain-
ing your encryption key. A personal certificate is similar to other types of certificates
used by computers in that it contains both private key and public key encryption
data. The certificate is extremely important. If it is damaged or removed from your
computer, you won’t be able to access your encrypted data.
Unlike NTFS compression, you can’t encrypt entire drives. You can’t encrypt com-
pressed files, system files, or read-only files either. If you try to encrypt compressed
Figure 19-18. Choosing the compression options