Browser cache

When you're surfing around on the internet, the pages you visit are stored in your browser cache. This means that pages you visit frequently will load more quickly, but it also means that anti-spyware and antivirus scans will take much longer. If you're running short on hard drive space, or if you're about to start an anti-malware scan, you should empty the cache of your browser.

Emptying your Internet Explorer cache

In the menu bar at the top, go to Tools > Internet Options...

Make sure you're on the General tab. Under "Temporary Internet Files," click Delete Files... Click Ok in the box that pops up. Your cursor will turn into an hourglass while the cache empties, then will return to normal when it's done.

Emptying your Firefox cache

In the menu bar at the top, go to Tools > Options...

Click on the Privacy icon on the sidebar. At the bottom, click the Clear button next to Cache. While you're here, you can also adjust the maximum amount of space your cache is allowed to occupy. When you click Clear, nothing will appear to happen. This is normal. Once your cache is cleared, the Clear button will be disabled, since there's no longer anything to clear. Click Ok, and you're set!

Emptying your Safari cache

In the top menu bar, go to Safari > Empty Cache...

You'll be asked to confirm your decision. Click Empty to finish emptying the cache.