Most websites use some means of storing pieces of information for later use, cookies is one of them. These are small text-files stored on the users system.
There are two types of cookies, the persistent cookie and the session cookie. Session cookies are deleted when you close your browser, while persistent cookies are stored for later use, either until they expire, or until you clear your cookies.
Generally its safe to allow cookies, and there rarely is any reason to clear your cookies. Most websites store personal information on the server in either files, or databases. The cookie often only contain the id for the session file, or database post.
Clearing Cookies in IE7
Note. You may need to login again after doing this.
Click on Tools < Internet Options, in the General tab you will find a section called Browsing History, now click on the Delete Button.
You can chose between various options, including Cookies.
You can also disable cookies entirely, and/or only allow specific sites.
This is done by clicking Tools < Internet Options, and then clicking on the Privacy tab
The Sites button will allow you to block and/or allow specific sites, by entering their URL. While the Advanced Button allows you to specify whether you want the browser to ask, or simply block or allow without disturbing you.