DELL N5010

My new DELL N5010 laptop was delivered and I could work only for  half an hour, with windows 7 files were loaded with a user name and a password, at same time I loaded the virus guard trial version for 30 days, everything  was fine when a message popped up asking me to re-start the computer to activate the virus guard. I restarted the computer and when I had to enter the password, it didn't accept it. I have been trying my very best since, and I do not have a password reset disk, since it was too late to create one for my laptop. I called technical support and to reboot Windows 7, but it didn't work out.

How do I resolve this problem? I am currently facing a crisis here, and it would be well if you reply sooner.