http://www.howstuffworks.com/file-compression.htm/printable
Yes, it will compress files, by how much depends on the file type and structure.
The pack command's algorithm uses Huffman encoding to compress files. This algorithm has fundamental limitations. Consequently, the pack command can only consistently compress files under 8MB. To consistently compress files larger than 8MB, use the compress command.
Winrar
Individual files and folders.
how do you compress all your files? I have a lot of files to Compress!
keep the files in the compress folders
The best answer is to compress the files ( Lops Leonel)
Files that are already compressed, such as multimedia files like MP3 or JPEG, are typically harder to compress further because they lack redundancy and patterns that compression algorithms can take advantage of.
Compress your files on the hard disk.
Compress old files means that some files the windows system thinks you havnt accessed for a while (such as files in 'program files' or 'WINDOWS') gets compressed. this will not move the files to a 'zip' or '7zip' files. itll just be compressed in the folder it was in!!!!!!
winrar, wizip, 7zip, Izark...
right click on the file, and click "Zip (filename)" and it will compress it to the same folder that the original is in.