If you have chosen to clone a whole disk, you are said to be in "Disk Mode". You are going to copy all the partitions, sector-by-sector from the selected source disk.
You might consider Disk Mode as an automated mode. In Disk Mode, your only choice is the location of the target disk where the archive is to be written and then confirmation to proceed.
Things that are automated are:
The clone operation must have exclusive access to the target disk while writing to it. Before you confirm the details of the clone operation, disk image software Active@ Disk Image attempts to lock the target disk for exclusive access. If another application or the operating system is using the target disk, you must close all applications or system processes that may be using the target disk.
If you cannot lock the target disk after closing applications and system processes, there are other alternatives that you may try:
Although force volume dismount will work in most cases, it will not allow exclusive access when you are writing data to a system partition disk or to a partition that is involved with system memory pagefiling.
If you are dealing with either of these two cases, you may run data backup software Active@ Disk Image from a bootable CD or start your computer in such a way that the target partition is not part of the operating system.
You can do this on a computer with multiple systems installed, by booting a different system or you can remove the target disk and install it into another computer where it will not be a system disk.