Local administrator rights

I have set up a laptop for a loan person at our bank. It is a Dell insperion, loaded with a wireless cell card for accessing the internet away form the office. She has local administrator rights to the laptop and full access to the C: drive. I have two profiles set up for at the office and away for the office. I have installed Nortions internet security and have a USB lock on the laptop. The problem is that at the office she can not reconfiger the internet explorer proxy settings to let her have access to the network. If I use the laptop as myself, I have doman admin rights I can change any thing. She can when booted to the network do any thing she needs to, like add, delete modify. She has had more rights added to her profile because she works after hours and makes the bank a lot of moneyp;) If she boots to the network, ie cable in and cell card out she can do what ever she needs too. I can give a lot more info, we are trying to be SOX, FIDC and every one else compatable.