Or if u are comfortable with editing config files then:
Go to C drive and open a file called bbot.ini..its a system file so make sure that u have enabled the option to see system and hidden files. That file will look like:
[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(3)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(3)\WINDOWS="Microsoft Windows XP Professional" /fastdetect /noexecute
C:\="Microsoft Windows"
Just change it to:
[boot loader]
timeout=0
default=C:\
[operating systems]
C:\="Microsoft Windows Whatever"
Restart and see!!!
Krish