"Please insert CD to drive G" help how can I play my DVD...

Your computer says CD when it also means DVD. I suppose it should really just say 'Put a disc in your CD/DVD drive G.' If you have only one DVD drive then that will be G. If you have two DVD drives then you will need to look in My Computer to find out which is which. I put lables on mine to remind me. Drive letters are Windows way of identifying each way of putting data into the computer and go right back to MsDOS days. A and B drives are floppy drives (which was all you had before hard drives were invented), C is your first hard drive with Windows on it; D is often now a partition with the factory copy of Windows for recovery purpose; E is often the first CD/DVD drive; F and G and maybe H and I are slots for flash memory cards of different sizes as used in cameras; and so on right to Z. Every computer is different depending on what equipment is fitted. If you add on an external USB backup drive it Windows will issue it with the next free letter of the alphabet.

there's only two possible answers for that kind of problem "Please insert CD to drive G". 1. Your optical drive is a CD/ROM not a DVD/ROM. CD drive's can't read DVD disk. 2. Your optical drive might be broken and you need to replace it.