I am new to the computer thing and I would like to know how to check their activity on the computer. I guess I am nosey.

If they are adults, and have basic computer skills, you will probably not be able to keep track of what they are doing without some type of netnanny or site blocking or tracking program.

If they have intermediate computer skills, even those can be worked around.

If they are adults, you really shouldn't be spying on them, unless they are still living under your roof, at your expense.

If they are adults, and have basic computer skills, you will probably not be able to keep track of what they are doing without some type of netnanny or site blocking or tracking program.

If they have intermediate computer skills, even those can be worked around.

If they are adults, you really shouldn't be spying on them, unless they are still living under your roof, at your expense.
They are living under my roof at my expence and I do not believe they are being truthfull with me

What you want to do is probably against the law if you're in the USA (can't say about other countries). I'd get a good lawyer to advise you first. Legal aspects aside, how do you think doing this can possibly be a positive thing for your relationship with them?

Do you own the computer? And what sort of activity are you looking for?

But basically if you have adult children at home and you are having trouble with them what rules do you have set for them to allow them to stay there.

While what everyone said is well and good (like do you own the computer, which is an important point, whether they're your kids, your roommate or your dog), you ended your question with "I guess I am just nosy."

In my opinion, just being nosy is a lousy reason to invade someone's privacy, even if they are kids. And especially since they are adults. My mother was nosy and sneaky. And I had an absolute terrible relationship with her, for those reasons among others. She was always messing in my stuff and listening to phone conversations. This certainly did nothing to help our relationship at all. (I once almost started a private conversation about "being pregnant" just to totally freak her out and teach her a lesson. In the end, I just couldn't hack that kind of lying and game playing. So instead I just confronted her about her evesdropping and she lied.)

I know what this feels like. Don't do this to them. If your only excuse is being nosy -- spend some time thinking about how you would feel if someone wanted to get into all your business. Especially given that they are adults. The fact that they are living under your roof doesn't change the concept of respect for privacy.

Sorry if this sounds a bit harsh or offends, but I've been there, having a nosy mother, and I know exactly what that feels like, and I think if you think from their point of view, you will see what I mean.