Zero Surge technology does not rely on the ground line for protecting your computer.  It is safe for your electronics to use Zero Surge in a receptacle that is not grounded.  Grounding is a human (and pet) safety issue so you should consult with a licensed electrician to find out how to mitigate this safety issue.

You should NOT use an MOV-based surge protector in an ungrounded environment.  This type of protection is called shunt mode which diverts the surges to the ground line.