I wanted to add another hdd 1.5tb to my system because I need the extra storage for video. I formatted it but when I came back to it this morning it had split it into 3 sections. Something I never did. I deleted one of the partitions and it combined with another but the the other won't work to extend to. I try to format it but it says it is too small but it show 880gb. What am I doing wrong?