My LG GSA 4167B is driving me to distraction. I had the need to burn a Double Layer disk and after trying unsuccessfully cannot burn ordinary DVD-R. I get an error message 'please insert writable disk. it now identifies itself as
HL-DT-ST-DVDRAM GSA-4167B DL11
Please anybody got any thoughts
Welcome to the forum 
Identifying itself as “HL-DT-ST-DVDRAM GSA-4167B DL11” is normal - my 4167B is identified in the same way (except I have DL13 firmware, not DL11). HL-DT-ST = Hitachi LG Data Storage.
You mention both DVD-R and DL discs, you can’t burn either? Have you tried different brands of disc?
The fact that it still asks for a writable disc leads me to ask - do you have any virtual drive/emulation software on your PC, such as Alcohol or Daemon Tools?
If you do, don’t uninstall them, a simple setting may need changing.