WD power supply model?

I have a 500GB desktop HD that I have not used in some time. I cannot locate the power supply that came with it, are all the power supplies the same ? Are they 12 volts? I need to find one in order to upload all my files to my newer computer, thanks for the help.

See if this helps http://wdc.custhelp.com/app/answers/detail/a_id/1378/session/L3RpbWUvMTMyMDE3MTc3OS9zaWQvak9TMVcxSWs%3D