Go to start menu and select control panel. Next select user accounts. Make sure his account is a limited account. Select his name and you will see his account details. If you need to select change account type and select limited and not admin.

Next close out and right click on any FREE part of the taskbar, the bar at the bottom of the screen. Select properties and hit the start menu tab in the top box. Now go to customize I use classic menu so I will explain it that way. At the new screen select use personalized menus. Close out of this screen.

Now you need to go into Windows Explorer to set up the menus, start menu - programs - accessories - Windows Explorer. Once in Explorer you will need to navigate to Documents and Settings, usually found in right in the c: drive. Once there you will see a listing for All Users, Your Account Name and Your Son's Account Name, you may also see other accounts names if you have them created.

Each account has a start menu directory. You should start with the Start Menu directory in the All Users and make it as limited as you want it. Placing the directories or programs you only want on your side of the computer in the start menu for your user account. Once your finished with the All User Start Menu select your sons User Account Start menu and do the same thing of removing files and programs you only want you to be able to see! Place them in your start menu in explorer.

So with all that done your son should have a limited menu of programs that you want him to use. To keep things neat do this after you install a new program only you want to use. Only make edits to the start menu from Windows Explorer, as you can easily make changes that are not intended.

Remember though that this only keeps programs away from him in the start menu, he can always open up the find comman or my computer and find all the files and programs you want to keep away from him. Only Windows XP Pro or Windows NT allows you the added security to make sure he can't see stuff on the computer unless he is logged into your account.

Hope it helps and makes sense!