@streamerz In the windows client at the bottom there is an option to plot drives. Select the drive you want to plot. On the next step select the amount of space you want to plot, small in this case could be 20 GB. Once the plot is finished start the miner to see if everything is working ok ( ie you miner submits a deadline and it is confirmed by the pool). Once all that works you can plot the rest of the drives.
Good luck and any questions just ask.
S