Privacy is at a premium. Whether it's the NSA, a hacker cabal, or corporate marketers, someone is looking over your shoulder every time you use your PC.
You can minimize your exposure, though. Whether you'd just like to keep your Web browsing under wraps or you want to obliterate all evidence of digital activities, follow these tips to stay on guard and off the grid.
Conceal your Internet activity
Covering your tracks on the Web starts with your browser's private browsing feature. Internet Explorer, Chrome, and Firefox each have this functionality, which prevents the browser from keeping a history of the pages you view. You can enable private browsing from the main menu--in Internet Explorer it's called InPrivate Browsing, in Chrome it's Incognito mode, and in Firefox it's simply referred to as a Private Window.
Note that private browsing won't remove every trace of your Internet activities. Any files you save will remain. Private browsing also doesn't do anything to obscure your Web traffic from the server's side. Websites you visit will still have your IP address, and any unencrypted data you send is as susceptible to interception as it would be in a normal browser session.
A more covert option is to use private browsing in conjunction with Sandboxie, an application that prevents other programs from saving any data to your disk (including malware that might try to sneak in from the Internet).
Finally, there's Tor, a network that allows you to browse the internet completely anonymously. While you're running the Tor software, any outgoing or incoming network traffic is first bounced among many other computers that people have set up to act as nodes in the Tor network. Any sites you visit won't know your IP address (which can be used to find out where you live), and anyone listening in on your outgoing traffic (including your ISP) won't be able to tell what sites you're visiting.
But while Tor may be the biggest weapon in the battle to protect your privacy, it's certainly not the fastest. All that server-bouncing slows down your browsing considerably. Unless you're a dissident in a repressive regime, or someone else with a life-or-death need for Web anonymity, you may well find that Tor is more security than you actually need.
Put your data on the down low
The next step is to protect the personal data on your PC.
You should have unique user accounts with passwords set up for each person who uses your computer, including guests. (Windows guest accounts have lesser privileges.) By default, any file in the C:/Users directory (which includes My Documents, My Photos, and all related folders), is accessible only to the user account that created it. It's not airtight security, but it will reduce access to your files.