Get the original drivers from here
http://www.dlink-india.com/support/supportdownload.aspx
Unplug your usb modem and uninstall it from the device manager you showed above and also anything installed in add remove. Run a registry cleaner to clean up the registry.
Reboot.
Now install the drivers. If there is an .exe file, run it WITHOUT the dsl modem plugged in. It will automatically prompt you to plug it in. Else you have no choice but to plug it in and install.
If the same thing happens, right click on it in device manager and select update driver and manually browse to the driver and try.
If all this does not work get a LAN cable (I think straight crimp, not cross), it only costs Rs. 5 per metre