I beg for help.

No major boom happened.
I set up limited accounts for each member of my family.
After the teenager was downloading and got a virus from Boo only knows where.

I went to one of the accounts to set up what my honey would need and have discovered the inability to get to the internet.

Have I done something wrong?
I have searched Microsofts site and found no real answers.
Either that, or I am not wording the question right.

How do I make sure that each of my limited account users can access the internet, WITHOUT making them computer admin.?
Do I have to make them account admin for a short bit, set things up and then switch them back?

Any help would be greatly appreciated.
Thank you for your time.
Ali