Ok, here is the problem i have(if you want just the problem don't read the next paragraph;

There is a Asus laptop who belongs to one of my friends. 2 years ago he sent the laptop to service for broken screen, and then everything was ok for 2 years. But now he wants to upgrade to win7 because his xp does not work anymore, but we had a problem when we tried it. The service has put a bios password 2 years ago and we couldn't figure it out. Maybe the service didn't put the pass, we don't know but we know we cannot enter to the bios.

Whatever, we can boot the machine until the welcome screen, the machine locks at that screen, we tried some options like safe mode, didn't work.
We only want to boot our pc from dvd, nothing else.

Thanks for your time

We have figured it out, so if any of you have the same problem, take a deeper look into first screen (the screen where your pc counts its ram etc).
There should be a line that says something like this;
"Press **** for Boot Options
And if you push the button on time, there you go :D

Thanks to anyone who reads this :D