A:
No, it does not. If you have a downloaded copy and put it on a DVD but the DVD is not bootable, you most likely did not create the DVD properly. Most downloaded installations for Windows are in ISO format, which are meant to decompress as they write to the disk, making it bootable in the process. If you simply put the ISO file on a DVD file, it is virtually useless. IF you did burn it properly but cannot boot, you either do not have your BIOS set to boot off of DVD or you have a DVD drive that does not support boot (rare) or, more likely, a faulty DVD drive.
Assuming the DVD itself is your problem, you can either download a new copy from another PC. Most likely you need an OEM disk (disk from the manufacturer of your PC), though, which can only be obtained by contacting your manufacturer. If you have a warranty, you can many times get these for free. Otherwise, they will usually charge around $20.
My only other suggestion would be to ask someone else you know that has a PC from the same vendor (not even necessarily the same model) that has the Windows 8 disk to let you borrow their installer. USE YOUR OWN WINDOWS KEY, otherwise you get into software piracy, which is illegal.
I hope this helps.