91% of Internet users told Pew Internet & American Life Project they have made at least one change in their online behavior to avoid unwanted software programs. 81% of Internet users say they have stopped opening email attachments unless they are sure these documents are safe. 48% of Internet users say they have stopped visiting particular Web sites that they fear might deposit unwanted programs on their computers. 25% of Internet users say they have stopped downloading music or video files from peer-to-peer networks to avoid getting unwanted software programs on their computers. 18% of Internet users say they have started using a different Web browser to avoid software intrusions.
52% of home Internet users say their computer has slowed down or is not running as fast as it used to. 51% of home Internet users say their computer started freezing up or crashing, requiring them to shut down or reset. 25% of home Internet users say a new program appeared on their computer that they didn't install or new icons suddenly appeared on their desktop. 18% of home Internet users say their Internet home page changed without them resetting it. In sum, 68% of home Internet users, or about 93 mln American adults, have experienced at least one of these problems in the past year. 60% of Internet users who report computer problems do not know the source, but those who do know cite viruses, spyware, adware, operating system flaws, and hardware glitches. Not everyone attempted a fix, but those who did often found that they needed help, paid or unpaid. About 28 mln American adults ended up spending money to get their computer working again, typically in the range of $100.