If you are the registered owner of the laptop you are probably better off contacting Dell support.

 

read the FAQs in the laptop forum

 

I called them but they said they will format it which mean i will loose all the data in this computer

another thing can i reboot this computer using the usb

 

You can reinstall Windows by using the OS CDs that came with your system when you purchased it from Dell.

 

this computer doesn't have internal cd driver....and that one of my problem

 

Have you tried booting to safe mode?

Dell systems usually have a pre-loaded image of the factory settings that you can access by pressing certain keys during boot up.

 

I did but didn't work .

 

You can just hook up an external USB CD drive and install Windows.

 

The Windows logon password can be accessed by downloading one of these tools: https://www.techspot.com/vb/post633339-2.html (preference to LiveCD)

If you are talking about the Bios Admin password, you will need to post in this thread only => HP / Dell / etc. laptop password help thread

Which password are you talking about?