i am currently running linux and windows on my comp right now but when i boot up the computer set linux as the default OS, I dont mind booting straight into linux but since its a family computer i was wondering how to set the default OS to boot into DOS, i have looked all over but the code to change the default does not work in my red had bc it says i do not have access which i believe is complete crap the boot file in linux has a red circle with a white "x" on it not allowing me to access it, just wondering if i can change the default OS through windows or linux and how to change it thank

You need root privledges to edit system files.
Either log into to Xwindows as root or open a command prompt and type "su" then your root password once your prompted for it. And I don't think you want to edit the boot file. What distro are you running? your bootloader is either lilo or grub.
If it's lilo edit /etc/lilo.conf then when your done run the command "lilo" if it's grub edit /boot/grub.conf If you need more help feel free to post.