That looks like you have two partitions, or Windows thinks it does.
Right click on My Computer then select Properties. From there go to the Advanced tab and then Startup and Recovery. In there you can set the time delay and default OS to select. If you click on edit you can manually edit the text file, but I am not sure what you need to add to comment out the second line. I think you just add REM to the beginning of the line, but it's been a while.
goates