http://www.techradar.com/news/the-best-free-winzip-alternative

WinZip is the best-known software for creating and opening compressed file archives, but it's not cheap and there are many superb free alternatives worth investigating before you open your wallet.

Windows (from XP onwards) has a built-in compression tool, accessed by right-clicking one or more folders/files, and selecting 'Send to > Compressed (zipped) folder'. This is fine for very occasional use, but is very limited. It can only read and create ZIP files (there are dozens of other formats), it doesn't let you create multiple volumes of a particular size, can't repair damaged archives, and doesn't support encryption. In fact, if you use it to compress an encrypted file, it will be decrypted when extracted.