


Space allocation will depend on how your drives are configured and what installation method you are using, however "space allocation" in the general term means how much space you give Ubuntu to be installed on and use. "selecting drive" usually means selecting a partition to install Ubuntu onto. So to answer your question you will need to format drive G: as ext3/4 before installing, which the installer will manage. Just select "Try Ubuntu without installing" after booting your installation disk/LiveCD. If you just want to try Ubuntu temporarily you can run a live session, running it off of a LiveCD (which you create when you burn the ISO to a disk) and play around with it without touching your existing Windows installation. If you are using Ubuntu 12.04 you can use WUBI to install Ubuntu on a virtual partition within Windows, however this method is not recommended. If you have multiply hardrives in your computer you will need to select which disk you would like to install to, otherwise "selecting drive" refers to partitions.

The installer will handle the formatting. Ubuntu uses the ext3 or etx4 format, unlike Windows which uses NTFS. Longer-term, we plan to do native drive-locking, so that Etcher will be able to grab exclusive access to the drive, and (I think) Windows wouldnt then ask you to format it. If you would like to install Ubuntu alongside Windows on a partition you will need to format your partition.
