Protect your Account Name & Password!
There are some people around to try and steal other people their accounts, they install software on your computer that reads what you type, so if you log-in, they can see it (keyloggers). To make it a little harder for them you can use a so called "On-Screen Keyboard", you need to mouse-click on a keyboard, on the key you want to enter. If you use this to log-in, a keylogger won't be able to log your account name and password.
Windows XP or Vista: Start → All Programs → Accessories → Accessibility → On-Screen Keyboard.
Or: Start → Run → osk → OK.
Don't forget the people sitting around your computer can still see what letters you're clicking on.
Remember, the best method of prevention for a hacked account is to never install software you have no reason to trust.
Keep in mind also, that around 95% of keyloggers used to get your account data read it directly from Tibia client memory, so "On-Screen Keyboard" will not help you prevent from this type of keyloggers.