There are people in my home that use my computer. They accidentally disable critical programs, accidentally download things they should not, approve/accept changes that they should not. I have to figure out what they did and how to reverse it. I don't want to worry about new surprise changes to the comp every time that I sit down. I use XP Home. What can I do so that people in the house cannot make any changes, but they can still use the computer for three things, looking at stored pics on hard drive, surfing the net and checking their e-mail.