Toshiba won't boot rather it beeps on startup

Hello,
My issue is that my toshiba laptop it won't boot up rather when ever i hit the power button only a screen appeared with toshiba written on it and then it shows blank screen with unlimited beeps,i tried to solve it by unplugging all power sources(battery,charger) and holding on power key for 1-2 minutes then i inserted both the battery and the charger n held on the esc key n pressed the power button it then showed me the directly the password entering screen n it hanged i tried to enter password but of no use then i again turned it off and did the same procedure again but when i powered it on it just showed the windows start up screen with written error as "some software or hardware issue prevented windows to start" and with windows 7 and windows repair options,i pressed buttons but in vain,again i selected windows repair but it started processing but again laptop started beeping unlimited times,please help me with this issue,i don't wana loose my files on my system as i am a student,please somebody help me.
Thanks
Regards,