Returning toshiba laptop to factory setting

Im running a Toshiba satellite laptop a305-s6872 to its factory settings, but i dont have the cd. i tried shutting off the computer, and then holding 0 and clicking the power button. the computer starts beeping, but when i let zero go, nothing happens. so instead, i try clicking f8. i click repair computer, but the only options that come are these:
1.start up repair
2.System restore
3.windows complete pc restore
4. windows memory diagnostic tool
5.command prompt
6.toshiba recovery wizard


so, i have no idea what to do.