Will you also install grub? Maybe you can edit the grub.conf/menu.lst so it still boots the loader first but to be honest I'm not sure. You'll have to ask Daz himself.
No problem Just install it. Everything will be okay. Unless you remove Ubuntu. Then you have to write a new boot- and mbrsector with the commands Bootrec.exe/FixMbr and Bootrec.exe/FixBoot (using Win7 dvd). After that you have to patch Win7 again. But hé, why should you remove (K)Ubuntu ? Have fun !!!