If the code is on the computer -laptop might have it on a sticker underneath??
my refurbished/used ones all had the code sticker on the bottom..

If it has that code , all you need is a windows cd from a friend to reinstall then enter the code on your sticker. Perhaps the place you bought it from will give you a copy..you don't need to buy a new windows cd/DVD.

but often there is a restore section on the hard drive, and you are supposed to burn a disk of that before the system has a problem..
I don't know if yours has that option or not..

When you buy a used or refurbished pc the seller usually has a generic copy of windows that they put on all machines, then enter the separate code for each machine to activate it...

Or if you have a large library or magazine book store that has computer books/magazines - some might have Linux Live cd inside to try......
all you do is put in the cd and reboot it will load and run from the dvd drive so you can test it to see if you like it..
rarely need anti virus software - the disk will find all your hardware and set it up.. rarely need to install any drivers like windows..
The only issue might be if using wireless , sometime the wifi card/chip is an oddball one so may not connect to wifi easily, but wired will work fine.

My Dell laptop had a problematic wifi chip/card so changed it out for an intel wifi chip and all works great..

My fav Linux is Mint Mate 17.1 newest version - long term support (LTS)
http://desktoplinuxreviews.com/linux...amon-and-mate/

Top Ten Distributions of Linux- info pages-
http://distrowatch.com/dwres.php?resource=major