Help: to make comp boot automatically, select an user account among other accounts

[bonny]

Hi, new user here..
I'm using windows 7 ultimate. I am trying to use task scheduler to run some programs at night when im not using the computer. I have already read some articles on how to make the computer boot up at a specified time (by using the boot menu). But my problem is that i have two user accounts (one for me and the other one for my bro) and i cant find a way to login to mine automatically. Please help.
Thanks in advance