In reply to tonerak:
First up - grab another browser, Firefox or Chrome will do. You don't have to use then permanently but while you have a problem with IE then you can browse until you fix it.
Editing the registry is a case of "here be dragons" if you don't know what you are doing. In most cases changing values is relatively harmless but some of the things you can change or delete can really stuff your system. The basic tool for editing the registry is Regedit, it comes installed with Windows so you don't have to download anything. The registry is a big table of key-value pairs so you need to find the key or keys that are in the instructions and delete or update those. You might have to be running an administrator account to do this.
On the subject of accounts - does your son have his own account on your laptop? If he doesn't then make one for him and password protect your account - both accounts should be "user" rather than "admin" as it reduces the risk of things like this happening.
