WinRAR is a nice compression software as it supports various of file types,such as *.zip,*.7z,*.iso...
After its 40days of trial period expires,WinRAR still can compress and decompress files.
The Layout of WinRARTo create an encrypted archive,click at the "Add" button.And the following window appears.

Go to the "Files" tab to add files that need to compress and click the "Append" button to browse the file's location.

To encrypt it,go to the "Advance" tab,and click the "Set password..." button and enter your prefered password.Be sure you to set your password wisely!

WinRAR marks a star beside an encrypted file.When you open that file,it request for password.

Sometimes we need to split a big file into seperate volume for certain purpose,such as copy to a diskette which is a small capacity storage media or e-mail which only allow a maximum filesize of 10MB per file.Remember only RAR files can be split,zip files doesn't support this function.At the "General" tab choose the archive format as RAR and click or type each splited files volume.

The splited files are named with *.part*.rar,all those splited must be gather together in order to retain the original file.