Editing Files for newbie

I have searched for quite a while but have not found an answer that works for me. If I should be looking or posting elsewhere please tell me.

Installed F17 on Dell laptop after installing Windows. Am in my mid-eighties and trying to learn Fedora and other open source materials.

The Grub menu lists my OS(s) but defaults to Fedora 17 (2 entries). I would like to default to Windows until I am comfortable with Fedora.

Trying to edit the Grub file, I log in as su with password OK. Following the direction of others, I have done the following:

[xxxx@DellLaptop ~]$ su
Password:
[root@DellLaptop xxxx]# cd /etc/default
[root@DellLaptop default]# gedit grub

(gedit:8906): EggSMClient-WARNING **: Failed to connect to the session manager: None of the authentication protocols specified are supported


** (gedit:8906): WARNING **: Could not connect to session bus
[root@DellLaptop default]

Could I please get some help as to how to solve the above message, edit the boot loader file and make Windows the default for booting. Thanks