Any idea why a memory stick would work in 4 different computers and not in another one?

I have a memory stick (60 meg) that works in 4 different computers, yet, when I try it a 5th one, the light just flashes green then turns orange, computer doesn't even recognize it. Any idea why this would happen?

Any idea why a memory stick would work in 4 different computers and not in another one?antivirus

could be not the right type or pin configuration

Any idea why a memory stick would work in 4 different computers and not in another one?computer

I agree with what Kcracer1 posted and well is the one computer a PC or Mac Windows is not friendly with Mac a windows PC wont read anything that is Mac formated
When I bought memory for my computer, they said that the age of the computer made only certain types usable. Go to www.4allmemory.com to find the specific memory sticks that will work in a specific computer.