If you only use linux sometimes and want windows to be your default, you can change the default boot option to windows by changing /boot/grub/menu.lst
--Find the line that probably says "default 0", then change the 0 to the windows option. Count up starting at 0 every time you see a "title" line towards the bottom of the file. Include the "other operating systems:" line in your count.
root password in ubuntu is a little retarded. In every other linux I've ever run, this can be modified by running visudo as root, and putting in a nopasswd option.
in Ubuntu when you run visudo, you should see a couple lines like:
# Uncomment to allow members of group sudo to not need a password
#%sudo ALL=NOPASSWD: ALL
However, I'll forewarn you that even when uncommenting that I've still been prompted for a password (and yes, I'm in the right group). For other folks watching who might know more: I initially put in my explicit user with a nopasswd option before seeing the above line. Having my user in the file, I was still prompted for password... what the hell is ubuntu's issue?