After the introduction of Internet and facility to browse any web sites the need for more storage space has been felt. The Internet offers more information that can be downloaded and stored by the users. This calls for the need for additional storage. External hard disc is an option. A normal hard disc can be used as an external hard disc by mounting it in a hard disc enclosure. External hard disc drives with more than 500 GB of storage capacity are commonly available today. The advantage of external hard disc is that the data is easily portable. It is also possible to install operating systems in such hard drives and run them in any computer. Most of the external hard disc drives are compatible with major operating systems like Microsoft windows, Maces and Linux etc. The inter net is also the source for viruses. The external hard disc is an excellent option to store the back up files. Now days the external hard discs are aimed towards portability and higher amount of Storage.