My kids are on twitter,Facebook.Limewire,aim, etc.I'm constantly cleaning their computers up.These sites screw up the registry with adwares and trojans,viruses mainly from other peoples computers. .Also you need a good internet security and virus program.I like Kapersky it doesn't keep banging the hard drive constantly like symantec,norton.That program slows down your computer.I clean them up & 2 weeks later,their freezing up after they go back to those sites.Look under freeware for programs to clean up your computer free.Crapcleaner,spyblaster,spybot,ad-aware,auslogic defrag,registry cleaner.All Free.Save yourself money.