How many computer can I install Moi

 From:  Jhong (JAY07M)
8972.1 
Hello, I am a freelance 3D modeler and looking for a low cost Nurb based 3d software. I'm just curious if I purchase Moi how many computers can I install with single license and how can I backup the license because sometimes I upgrade, reformat my OS and sometimes we cant escape form a hard drive failure. Thank you in advance for your response.

Kind Regards,
Jay