Hi Peter,
There are a couple ways to enroll a device.
First:
1. From the device itself, log into securitycloud.symantec.com
2. Go to Groups, Users, Devices page
3. Click on the plus sign onthe top right
4. Select enroll this device
Second:
1. Login into securitycloud.symantec.com
2. Go to settings
3. Click on Windows installation package
4. From here select if it is a client or server
5. Download package
Once downloaded, you can use this package to enroll devices.
Also please note that you can transfer devices between different users.
Hope this helps. If you are still having issues please let us know.
Thanks,
Ashot