|Firstly 'Reboot' means restarting your pc so in the context in which you are using it is incorrect and misleading.|
You mean you need to format your machine. Have you tried the Lenovo website? i know manufacturers such as Dell will allow you to enter a service tag and allow you to download the software for you machine.
However i have not tried this with Lenovo but i assume they will have the drivers for your machine no doubt. The only thing you may not be able to get hold of very easily may be the Windows OS. You could send them an email and ask the question.
If all else fails it probably wont be a bad idea to download the drivers yourself, buy a copy of windows and have everything as hand for the next time you need to perform a format.
Can i ask why you need to format though? if you are having problems we may be able to help you fix them instead of formating.