After updating to Android 2.1, Windows XP no longer recognized my HTC Droid Eris.
1. download the USB Driver via the Windows Android SDK
2.check your Android's VID and PID via Windows Device Manager
3. Open android_winusb.inf in the usb_driver folder and check that the VID/PID combo exists in the file.
4. If it doesn't, add it in into the respective INI section. For example, I added this for Droid Eris under the [Google.NTx86] section:
%CompositeAdbInterface% = USB_Install, USB\VID_0BB4&PID_0C98&MI_01
5. Save and reinstall the USB driver and that's it!
If you're currently using Proxoid's windows drivers, they're not updated for Android 2.1. Try using the Android SDK version instead.
Also, you'll need to copy over adb.exe and AdbWinAPI.dll from the android sdk tools folder over to the proxoid-adb folder.