Make Sure you have Zune installed on your PC and then perform the following steps. This will disable the Zune Sync feature via USB, and enable Modem. Put the phone back into Diagnostics mode and select Zune sync to re-enable the sync.
- Dial ##634#
- Once Diagnostics opens, Dial *#7284#
- Switch to "Modem, Tethered Call" and wait for the phone to restart.
- Connect Phone to PC via USB and wait for drivers to install
- Create new connection in Network and Sharing Center
- Number to dial: *99***1#, User: WAP@CINGULARGPRS.COM Password: CINGULAR1, and connect.
Please Note: Windows 7 64 bit users will need to manually download the Samsung phone drivers and direct windows to that install directory during driver installation
If all goes as planned your new windows 7 phone can be used as an air-card.
EDIT: For those having issues downloading it directly from Microsoft Update (Recommended) here is a copy that you can directly download from my site.Samsung_Focus_Drivers.zip