Cookies and cache are temporary internet files that are stored on your computer to keep track of sites you’ve visited. Cookies and cache are meant to allow faster access to data and store site preferences. These files usually have an expiration date on them, so they clear on their own but you always have the option of clearing them manually. Follow the steps below to clear your cookies, cache and history in Firefox 3.5.

To clear cookies, cache and history in Firefox 3.5:
1. Open Firefox.
2. Click the Tools menu and select Clear Recent History.

Tools Clear Recent History

3. Click the dropdown menu Time range to clear: and select the range of history you'd like to delete.

Select Time range to clear

4. Click Clear Now.

 Clear Now

Poof! Your cookies, cache and history have disappeared in Firefox 3.5.