How save is playing games on the internet?

Sometimes i or the childeren from a friend play online for instance by MSN Gaming Zone or GameSpy, bought Microsoft games like e. g. Age of Empires .
I noticed several times that when i or they played, that sometimes strange things happen.For instance, the other player cheats and create "extra" gold or "food" for his citizens in the game. Or he (or she?) let the game say that his team is "victorious" although they actually didn't win.The strange thing for me (not a computerexpert ) is that in the game manual "Cheats-option" is disabled.


Now i am wondering, if some kids (?) can cheat that much, how safe is playing that kind of games for the rest of my system?

 

I used to play online games quite a bit. But I haven't in a long time, but I never had any trouble because of playing. If you have your computer secured well you should be allright.