I have a acer aspire 5250-0810 that

[maria_48]

Hello
my computer is showing me that it doesnt have a bootable device can you please help me out

 

[popatim]

you can try disconnecting the harddrive and pluging it back in and then turning it on.
Boot with a dvd based operating system that has an antiviris on it and see if its a virus causing it.