You don't ever need a CD to reboot a computer. You go to the start menu and choose restart.
I assume you mean reformat/reinstall windows/reset to factory settings. To do that, you have to have some kind of media with the windows installation on it. A CD is the easiest to get, a USB device is usable.
Why can't you use a CD? If it is because you don't have one, you can order it from Toshiba for (I believe $25). If it's because you don't have a drive (or have a broken drive), you can buy an external CD drive for about $40.
Toshiba uses OEM discs with all their bloatware on them, and each disc only works with the model of PC that it came with. (Pain the the ass, I know, because I have 3 of them.) I'm not sure on this one, but I THINK (someone please confirm) that you could use a system builder disc with your OEM key. Otherwise you'd have to find the precise disc, or purchase a new Windows key.