My Sylvania Meso G keyboard does not type properly

Only a few keys on my keyboard type at all. They don't type the correct thing. For example backspace types 123 in some permutation. Enter types a series of characters including carriage return, but also in random order. Only about 5 or 6 keys on the right side type anything at all -- never the right thing, the rest do nothing. Typing F2 to get into setup at boot-up also seems to do nothing.