Sounds like short-circuit in laptop

Hello,
yesterday i was in facebook when i heard a strange sound like court-circuit coming from my laptop and then the screen become blue and a lot of words appear i just read the first line: windows has some problems and it should be shut down. after that i have tried to restart but a new windows appeared to me and asked me if i want to repair this error i click ok the desktop appear but nothing working. i rebooted again but for sutdown it took about 30 min and to reboot also and after rebooting any application that i want to execute take 20 around and after that it will be blocked. i wanted to take my data but when i put my usb the laptop was blocked again.
i have an Dell inspiron n5010 laptop.
i really i don't know how to do because i'm afraid about my work, i don't have any other copy.

please i wants some help

thanks