Chess Tactics Server uses session cookies to track tacticians data. Session cookies are completely benign, despite all the bad press they've gotten. There is absolutely no way a session cookie can harm you or your system. It can't give away any information, it can't let a hacker in, it can't tell who you are, it can't find your credit card numbers, it can't do any other bad things. The only thing it can do is what it was intended to do: help Chess Tactics Server keep track of your performance.

On Microsoft's Internet Explorer, follow these steps:

On the menu, click on "Tools"
On the drop-down menu that just popped up, click on Internet Options
In the Internet Options window that just popped up, click on the Privacy tab.
Slide the slider down to no higher than Medium High. This will also enable simple Java-Script functionality for displaying and animating problems