I have the Muziq and I use it as a modem all the time. However, I struggled trying to figure it out at first because the instructions were indirect and never worked for me. I have figured out my own way of doing it and I will list the instructions here. This is for a Vista based computer, though any windows format will work, you just have to figure out where certain things are.
First, you need to have a data plan w/ phone as a modem. PAM is $15 a month and you need to get an unlimited internet data plan or you will incur HUGE charges.
Step by step instructions:
1. Plug phone into USB port.
2. Make sure the phone returns to the normal screen after it indicates the USB cable is attached. I have had issues with it not working unless the screen is back to its normal state. The only thing that should be different is that it will say USB mode.
3. Click on the network symbol on the bottom right of your computer screen.
4. Choose the option to connect to a network.
5. On the bottom of the screen this pulls up, select the option to set up a new connection.
6. Next, click on the dial up connection option.
7. When the screen pops up, enter #777 into the dial up number section, then in the connection name, simply enter anything you want, I use my name.
8. Click set up connection and it will go through the process automatically. This should set it up for you and you can now use your phone as a modem.
Keep in mind this is not the way sprint will tell you how to use it, but it is the only way I have been able to get it to work. It works very well too.
If you have any questions, let me know. Good luck!