Partition question

I bought a new 320GB drive to use as a backup to my 80GB drive.  I created a restore point of the 80GB drive (70GB in use) and tried to recover it to the 320GB drive.  I told it to restore the MBR, make it bootable, etc.  Something failed during the restore and now when I look at the new drive, it shows a total size of 70GB.  I thought I could delete the partition and restore the entire 320GB but it won't let me delete. 

 

How can I restore the new drive to it's factor size?

 

J