Selected boot image did not authenticate

[Guppi]

I used my laptop about 2 weeks ago & everything was fine. Today when i went to use it i was stuck with a black screen & blue bar. Ive read the other forums & can not get it to work. After pressing f10 & changing the legacy(?) Settings im stuck with a black screen that says; "no bootable device - insert boot disk & press any key) anytime i press something it repeats itself. I cant lose any of the information i have on my notebook as it is super sentimental & has huge value in my life. Im unsure how to procced & need it working for work! 

Thank you!!!

*to add; i recieved this laptop from a friend a couple years ago & am unsure of any details for the computer. 

[Lil_Boy_Blue]

Hi

If the Hard Disk was set/created with GPT and you change it to MBR style then it wont work.

"" I cant lose any of the information i have on my notebook as it is super sentimental & has huge value in my life.""

AND you have have no backups or printouts?  When the Hard Disk dies so does the Data.

What OS did it have?   EG:  W7 or W10 or....

There are repair / recovery discs out on the internet, but without a working device you cannot easily obtain one.

Perhaps a friend can help to obtain one.