Is there any critical data on the drive?
IF so, you should probably back that up before doing anything with respect to the partitions on the drive as they currently exist.
Acronis??
Acronis Disk Director? That is Acronis' version of their drive manipulation utility.
IF, all you want to do is set the drive up as one big warehouse to host backups or other data, you could use the native Disk Management utility from within Windows to delete the existing partitions and format the entire thing as one ntfs volume.
You should probably explain in a bit more detail, as to what your goal(s) might be.
And whatever you decide to do, make sure that you are directing your action at the correct physical drive so as not to inadvertently wipe your Operating System.