My friend has bought a surge protector bar... when he plugs it in an outlet the red light comes on but the green one does not... which means the outlet is not grounded.. is this safe to use or what should he do Thanks

I have seen wall outlets that have bad grounds and I have seen surge protectors that are defective. It might be wise to pick up an outlet tester for a couple of dollars just to verify the outlet.

Without a ground, the surge protector doesn't have all the tools to do it's job. It can protect against common mode faults where both the neutral and ground potentials rise. It wouln't protect against ground to neutral faults and COULD cause a dirty reference to be delivered to multiple GROUNDED equipment such as computers and TV's that share the strip.