As the name implies, this is software that “spies” on your computer. Nobody likes to be spied on, and your computer doesn’t like it either. Spyware can capture information like Web browsing habits, e-mail messages, usernames and passwords, and credit card information. If left unchecked, the software can transmit this data to another person’s computer over the Internet. So how does spyware get on your computer? Just like viruses, spyware can be installed when you open an e-mail attachment containing the malicious software. It can also be installed when you install another program that has a spyware installer attached to it.