How you can lose data with viruses
Most of the computer programs on your PC are designed to be helpful to you achieving your own aims. A virus is also a computer program which normally aims to engage in malicious activity.
In terms of data loss, your hard disk can easily be corrupted and rendered unusable, viruses can erase files or all the data on the computer can be deleted. Even if you don't loose data directly, a virus could prevent you from using your computer.
Almost everyone would have experienced a virus at some stage. They can enter your computer through many different avenues. The most common are through the internet and email or by loading a program or file from a CD, DVD, etc.
The great thing about online data backup is you can protect several historical versions of a file.
This means if a virus effected one of your files 7 days ago, you can use online data backup to restore the file as it was 8 days ago before it was affected!
Professional online data backup