Is there a way to prevent companies from seeing anything you do on the computer?

[Health Guy]

There's two different situations here:

1) If you're talking about software that you install, then you can uninstall the software. For example if you install Real Player, Real can probably monitor some anonymous data about what you watch for marketing purposes. If you somehow disable this behavior, the program might not work properly

2) If you're talking about surfing the web, companies use cookies to track what websites you visit for advertising purposes. This way, if you visit a lot of web sites about cars, you'll see ads about cars and you're more likely to click those relevent ads. You can disable cookies which might break some web sites. You can also use a proxy server which lets you surf anonymously so that those companies can't track you. They'll track the proxy. Try http://punchthrough.com or google proxy servers for more sites you can do this at.