I love HD2 and WP7, but I need tethering for my mobile working. I do search all google and XDA but no luck, then I decide to make it one. Lucky is in HTC Mozart have HTC Test tool, after 2 days code and fix driver tethering run well on my HD2 WP7. Then I want to share for you all, use your own risk.
1. Download XAP file in attach
2. Download HTC Sync for Android from HTC for USB Modem driver
3. Deploy XAP file to your phone
4. Turn of your Data conection in your phone.
5. Run DFRouter and click on "HTC Modem"
6. Open your device manager, it will show 2 unknown device, choise device have ID is : USB\VID_0BB4&PID_0EFF&REV_0000&MI_01, update your driver with HtcUsbMdm and you got HTC USB Modem.
7. Make a dial up call from your computer and set it work like other WP7 tethering from samsung or LG.
8. Click "Zune Mode" to come back with Zune Sync.
For dial up make a call *99# with mi_01 id modem. Mi_00 is diag port, maybe have some qualcomm unlock here. Don't forget add +CGDCONT=1,"IP","your apn" in your advance property of modem.
For modem disconnect error let turn of your data connection in your phone, crazy but it work. Not sure it charge or not from your provider.
Wifi have native code too, but need more time to to.
Will update version soon!
Important note: Don't unistall dfrouter before you back to Zun Mode.
I did test it work on my HTC HD2 WP7 and HTC Mozart and my Windows 7 x64, WinXP x32.