You can create the master image in either of these ways:
In Windows, by using Management Agent installed on the master machine. This type of imaging is called online imaging.
By using a bootable media (either Acronis media or WinPE-based media) with Master Image Creator, or by using the command-line utility in a WinPE-based bootable media. This type of imaging is called offline imaging.
Master image is created remotely. No physical presense is required
Master image is created without putting the machine offline
You can save the image file to the same disk that you image
This is the only way to create an image of a machine prepared with sysprep
To create an image of Windows XP/Vista/7 Home operating systems, you will need to install Acronis Management Agent locally (remote installation is not possible)
Physical presence is required
The machine has to be put offline
You cannot save the image file to the local disks. You can only save it to a network share or removable media