transfering files to network hard drive

i recently purchased a Iomega network hard drive and would like to transfer my files from my old removable hard drive to this new one.  i am using a dell inspiron 1525 laptop with vista home basic.  i have discovered that i can only copy files to this new drive instead of moving files.  in windows xp i know you can move files from one drive to the next.  i dont want to have to copy then delete files. is there an easier way to move these files.