If I am going to have my neighbor look at/fix my computer, what do I need to do so he can't view the internet sites I go on?

You need to clear your internet history. You can do it through your browser. What browser do you use?

You should really be clearing your internet history, your cache and other junk from your computer on a regular basis anyway. All that stuff can kind of clog things up and slow your computer down.

You also might want to run a clean up program.

Delete the history and the cookies from your browser(s). Copy your favorites into a file on a removeable storage device and delete them, then restore them from the copied file when he is done.

Go online. Hit the buttons CTRL and the letter H at the same time and your history will come up. Then clear/delete the history.

Clean out your pc of sites you do not want him to see, before he examines it.

Clearing history is not good enough, is he knows computers he can see it anyway.
There are so many ways to restore data and view deleted files… be careful!

I need my history. I try to keep it as long as possible for reference.
However, I do occasionally go through it and delete sites I don’t want or need or wish to have seen. I use firefox and go to history >> show all history and delete sites selectively.

Hell, you could even set up a “fake profile” by going to sites you want people to see you visited, while clearing those you don’t