how to bypass systems disable & admin password

Enter Administrator Password or Power On Password"  
 
Changes made to system that caused issue to occur: 
Laptop was stolen from car two weeks before Christmas, but was recovered by police and returned to me a month later.  Upon retrieval of laptop, the battery was dead and the power pack/cord & mouse wasn't returned with the laptop.  I had a dell power pack/cord that fit and used to turn on the computer.   A black screen appeared with a blue box asking to "Enter Administrator Password or Power On Password."   After 4-5 attempts to enter the password that was set for windows, the system disabled itself.   I would have to remove the battery and plug in power cord to reset the computer which continues to ask to "Enter Administrator Password or Power On Password."   I do not want to restore or reset the computer by losing all my personal data that was stored prior to it being stolen.   Is there anyway to override this or is there a "generic password" to use as a bypass this screen to get it to operate and back to the Windows login screen?   I REALLY NEED HELP ON THIS!