How can i create a CD-ROM/DVD bootdisk to boot straight to MS DOS?

Hi i recently installed windows 7 on my desktop and i accidentally compressed "bootmgr" and it won't let me start windows, even if i try pressing F8 to go into safe mode. I do not have the instillation DVD or anything like that. Is there a way to make a CD-ROM or DVD rom bootdisk to boot straight into MS DOS so i can uncompress the file? ( I dont have a floppy disk drive otherwise id use that)