lol, how old are they? When I was little I downloaded a keylogger to record my mom’s aol password (she had the master account where parental controls were).
Also, they might have created a new user and hidden it from the login list. This is done through the registry.
Most likely they did one of the above. Check the control panel to see how many users there are… Should just be the admin and your account.
They might also be using what is called a mobile OS, that they have on a CD/DVD or a thumb drive. The whole OS is on that medium, and when they start the computer they get the option to load that instead of xp. It gives unrestricted access to the Internet, but is not suitable for gaming.
It’s too easy for kids to access a computer, keyloggers, changing passwords. I used to change my dads administrative rights. Kids know more about computers because we grew up with them. But as to security, change your password, delete suspicious files that you didn’t download. And make sure your the administrator and that here are no other accounts, or you could create a limited account (which means your kids can’t access your files) for them. I hope I helped.
I agree with fortris. In ways, it’s almost impossible to protect a computer from kids because as any security expert knows, the most vulnerable computer is one that the perpetrator has physical access to.