How do i install and boot to DOS in NTFS format?

Hi every body.

I have a PC setup winxp on the first partition,formatted NTFS,i setup DOS 7 on the next partition formatted FAT32,but i dont know how to add this partition to the boot choice so that when the PC boot up,there are 2 choices for me:

1.Windows XP professional

2.Boot to MS-DOS

and i dont know how to setup NTFSDOS to access ntfs partition.When i buy PC,they do it for me but now i cant do that again.Brethen,please help me! Thank so much!