Some people write Kinect v1 and mean the Kinect One. i know you actually mean the Kinect for Xbox360, as the Kinect One (v2) is not supported, therefore will not work.
please make sure you have the Kinect 1.8 SDK installed (for driver support) and the newest Nvidia drivers loaded. If you are attempting to scan with a card that only has 1gb ram as the GTX550 shows, you cannot scan at Very high on GPU, as it does not have anough ram. Please selcect high or select medium quality if it fails.
To test your kinect to make sure it functions properly, you can test out the applications in the SDK to make sure you are receiving video signals,etc.
Also to note, the FREE version only saves a maximum of 5000 polygons, aka low resolution.
Please check your device manager and note that all 4 kinect devices show up under kinect for windows. if they do not, check the power adapter to the kinect. if only one shows up, or continually blinks between 1 and 4, its usually the power adapter