We cannot restore the laptop back to the factory settings, without the computer's username and password. We can however, re-install the Windows operating system with help of 'Windows Re-installation DVD'. If you have the Windows re-installation disc and an external optical/DVD drive, I will help you with operating system re-installation. If you do not have the DVD, please accept my friend request and reply through a private message with the system 'Service Tag' and 'Account Holder's name'. I will check the warranty status and system's specification; and will provide you with best support options available.
Do reply if you have any further questions. I would be glad to assist.
Thanks & Regards, Saurabh A #iworkfordell To know more about Dell’s products, services and drivers & downloads, click Here. For helpful Dell Support Videos, you may click Here