Spyware and viruses are the biggest problem with 2k/xp. If people are careful then the system has no problems. Its quite bulletproof on its own when its not riddled with viruses
Can you believe in this day and age,I know people who have windows (I do as well) and dont even have a router / firewall, antivirus or anything and they surf and wonder why 30 seconds later they are infected and the computer is screwd up! Thats fine to do on a mac but not on a PC with so many viruses around. Need protection.