When i turn the camera on it has it's default definitions.

Press cursor-right (marked with a lightning bolt) then select "Flash off."

http://www.olympusamerica.com/files/Stylus%20770%20SW%20Instruction%20Manual.pdf
Page 56 of this manual explains what to do.

Write protect

Either the software in both cameras need be updated. EIther by online software update program or the manufacture will do it for $50 a camera.
Otherwise, some SD cards to have conflicts with some camer'a software for some reason. Sometimes using the wrong sd card in a camera will result in memory flash and causing the camera to be in need of software update. Once updated you should be good and should work with all sd cards from now on.

Go to the support section of the Olympus web site to download a copy to your computer.

The switch may be going defective, or the circuit board that it is sitting on is defective. This would require factory level service. They will most likely change the switch assembly to get the camera working properly.

Jerry G.

I just spoke to Olympus Tech Support.

You have to download Olympus Master 2. (Their program is no longer called Camedia Master.)

http://www.olympusamerica.com/cpg_section/oima_softwareMaster.asp

At their main site, search for olympus master 2.

There is already a thread on this exact same problem at:
http://www.fixya.com/support/t181458-power_switch_not_working_in_power_off
The only solution noted was to see Olypus customer support (not really a solution at all)

According to Olympus, you must use the CLA-4 lens adapter tube to attach a filter to the C-770. The CLA-4 tube then will accept any 55mm filter.

If you are talking about converter lenses (telephoto and wide angle), there are a few that will fit the Olympus C-770. You will have to use the Raynox adapter tube instead of the Olympus CLA-4 tube. There are probable others, but I could not find them. Interestingly, the Olympus TCON-17 and WCON-07 lenses are very popular and adapted to other brand of cameras.