Compressing files and folders reduces the space they occupy on your drives (fixed or removable). Windows offers two compression schemes: Microsoft's proprietary NTFS compression (the same as in Windows 2000) and industry-standard zipped folders (new in XP). You can use either scheme or both; each has its relative advantages. NTFS compression is simple, transparent, and suitable for everyday use, whereas zipped folders are best for:
Emailing large attachments
Archiving files that you no longer need regularly
Transferring files over the internet or via FTP
Gaining the maximum amount of disk space
Compressing encrypted files
Some important points about NTFS compression are:
It's available only on NTFS-formatted drives, not FAT or FAT32 drives (Getting Ready to Install Windows XP" in the appendix.
You can compress individual files and folders or an entire NTFS drive.
It's easy to use but doesn't save much disk space compared with Zip compression.
NTFS-compressed files and folders act normally in Explorer, programs, and dialog boxes. Windows decompresses and compresses files invisibly and on the fly when you open and close them, at the cost of a small (probably not noticeable) performance hit.
Don't compress system files in the Windows (or WINNT) folder, because XP uses them frequently.
If you send an NTFS-compressed file to a non-NTFS disk (via email or dragging, for example), XP expands it to its normal size automatically and invisibly. A file sent to a compressed folder or disk is compressed automatically.
Windows XP disposes of the awful DriveSpace compression scheme from Windows 9
x.
can encrypt zipped folders). See "Encrypting Files and Folders" later in this chapter.
To NTFS-compress a file, folder, or drive:
1. Close all files to be compressed.
2. To compress individual files or folders, select their icons in Windows Explorer; right-click one of the selected items; then choose Properties > General tab, click the Advanced button, and check Compress Contents to Save Disk Space (Figure 5.40 ).
or
To compress a drive, right-click its icon in My Computer; then choose Properties > General tab and check Compress Drive to Save Disk Space (refer to Figure 5.39).
3. In the Confirm Attribute Changes dialog box, indicate whether you want to compress subfolders too (Figure 5.41 ).
Tweak UI" sidebar in "Using the Start Menu" in Chapter 2.)
If you've used the popular WinZip program, you're familiar with the concept of compressing files and folders in Zip format. Some important points about Zip files are:
A zipped folder, called an
archive, is a collection of files compressed and combined into a single file (Figure 5.42 ).
You can create archives on any drive, not just an NTFS drive. Archives stay compressed when you send them elsewhere. Mac and Unix users can work with them too.
Zipping squashes files much smaller than NTFS compression does. Zipping most image, music, and PDF files won't save much space because they're already compressed, but program, web-page, text, word-processing, spreadsheet, database, bitmap, and WAV audio files shrink a lot.
Though they're actually files, zipped folders still behave like folders in several ways. Double-click an archive to see what's in it (Figure 5.43 ). Double-clicking a document in the archive opens a read-only copy of it; choose File > Save As to save a copy elsewhere. (Or extract it from the archive to work with the original.)
You can password-protect archives to prevent others from extracting files.
To create a new zipped folder:
1. In Explorer, select where you want to create the new archive.
2. Choose File > New > Compressed (Zipped) Folder.
or
Right-click an empty area in the right pane; then choose New > Compressed (Zipped) Folder.
3. Type a name for the new archive (keep the .zip extension, if it appears); then press Enter.
Tip
To create a new zipped folder from existing files or folders:
1. In Explorer, select the file(s) or folder(s) that you want to archive.
2. Right-click one of the selected items; then choose Send To > Compressed (Zipped) Folder.
To add files or folders to a zipped folder:
1. In Explorer, select the zipped folder that you want to add files or folders to.
2. Right-drag the file(s) into the zipped folder; then choose Copy Here or Move Here.
If you zip files only occasionally, Windows' built-in tools work fine; otherwise, get a copy of WinZip ($29 U.S.; www.winzip.com), a superior utility that can:
Zip and email in a single step
Create self-extracting (.exe) archives that unpack themselves automatically when double-clicked
Use wildcard file specificationslike *.doc (Word files) or *.mp3 (MP3s)to bulk-add files to an archive instead of adding them one by one
Split large archives across disks for easy reassembly later
Encrypt and password-protect archives
Work with many compression standards, not just Zip
WinZip and zipped folders can coexist. When installed, WinZip takes over the .zip file extension and becomes the main way to handle Zip archives (see also "Associating Documents with Programs" in Chapter 6). To reassign .zip back to Windows, in Explorer, choose Tools > Folder Options > File Types tab, select ZIP in the Extensions column, and click the Change button. In the Open With dialog box that appears, choose Compress (Zipped) Folder; then click OK in each open dialog box. Windows is now associated with the .zip extension, but you still can use WinZip by right-clicking a zipped folder.
To password-protect a zipped folder:
1. Select any item in a zipped folder (not the folder itself).
2. Choose File > Add a Password; then complete the Add Password dialog box.
The password applies to every file in the archive.
Tips
aren't password-protected. To protect them, choose File > Remove Password before adding new files; then reinstate the password. The Has a Password column in Details view indicates a file's password status.
Password-protection prevents only file
extraction. Other people can still view a protected archive's filenames and even delete the files, bypassing the Recycle Bin.
To extract files and folders from a zipped folder:
To extract only some files or folders, double-click the zipped folder to open it; then drag the files or folders to a new location, where they return to their original sizes.
or
To extract all files and folders, right-click the zipped folder in Explorer; then choose Extract All (Figure 5.44 ).
Emailing Photos" in Chapter 9.