OK followed this, when I downloaded Zadig there was nothing in the drop down menu, i had to select list all devices, now STM32 virtual com port came up and I installed the driver. I am now mining BTC side but my Scrypt side now fails even with the --dual option added to the bat file!!!

Are you sure the comport is right? I also had a DM from someone with the same error, in that case the usb port was faulty. So try a different port as well.
The USB port is fine. The PC is brand new build, The device worked before through the port before I switched this driver
To bring you up to speed, check the link below and read the comments:
http://cryptomining-blog.com/1254-how-to-mine-both-btc-and-ltc-on-gridseed-5-chip-gc3355-asic/I think he meant, in the batch file. You have to look in device manager for the COM port, and see what number it is assigned, and the put that in the batch file. I think that is what he means.