Newbie needs help with registry issues

I am working with a third party device that works like a little scanner and is connected via serial port to the PC. It came with an ActiveX control that communicates with the device and gives me useful properties describing the image (e.g. size, fileinfo). The control stores its communication parameters (e.g. Port#, Baud rate, etc) in the registry. I have the code to make changes to those parameters in the registry.
Here's the problem:
I am trying to implement this device into a browser based application. The clients will have the device hooked up to their machines. I want to have a procedure that will look for the device and consequently which port it is using - no problem. However, if the client does not have administrative rights, I won't be able to dyanmically change the port settings in their registry with code. Any suggestions as to how I can work around this problem? I am new to this, so I am not sure where to start. I hope this makes sense!

Thanks,
Blake

What OS are your clients using, Win 9x or NT ? Asking because you are talking about administrative rights. If you are going to install it on NT then you need the administrative rights, there is no other choice. Maybe divide your app into two parts, one is your app and another is the portion that detects and manipulates the port settings. Your app install it on client machines, and the port management part install on the server and ask an administrator to run it.