A cookie is the name given to a very small file that stores settings and preferences made while visiting a web-site. Cookies contain only text used for settings and cannot be used to run software code (programs) or to deliver viruses to a computer.
The cookie feature was first established and defined by the Internet standards forum in 2000 as RFC2695. Internet Explorer 4 was the first version to include support for cookies, and soon afterwards the media began writing stories about the potential risks of this new feature.
The main risk of the cookie feature was that Internet Explorer 4 and Internet Explorer 5.0 would allow a web-site to check the contents of a cookie file that was created by a different web-site. This security risk was eliminated in Internet Explorer 5.01 and later so that only the web-site that created the cookie could re-read the information.
Disabling cookies may prevent some web services from working correctly, and disabling cookies does not make you anonymous or prevent Web sites from tracking your browsing habits. HTTP requests still include information about where you came from (HTTP Referrer), your IP address, browser version, operating system, and other information.
However, ten years later none of the potential problems or risks of using cookies in Internet Explorer have been seen. While recommendations to delete cookies persist, it is an unnecessary and ineffective practice that should be discontinued. Since cookie files are tiny in size (rarely larger than 256 bytes) there is no size or space consequence to storing them. They also cannot be used to execute code, so there is no virus risk. Removing cookies has no effect on performance. Programs like cCleaner from Pirisoft.com can be used to remove all cookie files and other temporary files.
A better approach to dealing with cookies is to use the InPrivate browsing feature in Internet Explorer. When enabled, Internet Explorer will not save or create cookies, and does not leave behind any browsing history when finished.
In conclusion, there is no benefit to manually deleting cookie files, and the result of deleting them can make browsing web sites more difficult.