I need some help

I have got a windows product key But no downlod to put on a disck or usb drive and i am doing a fresh install On to a new pc im bulding and i need to know wher to download windows 7 Ultimate or Windows 8 Professional

I have the key for them just no download Any help would be Helpful ecept a http://lmgtfy.com/ link Thx

here, look at the answer feild

 

http://answers.yahoo.com/question/index?qid=20130126144341AA8xmaP

No all i ned is the download I bought the key But i lost the disk and need a download