error disk AO725

[Gaz_2_]

when I turned my Acer Aspire One 725 netbook, on screen appeared this note, "a disk read error occured press Alt+Ctrl+Del to r

 

[penguintech]

you probably have a bad hard drive, just as it says, disk read error.
Try to boot into a hirens disk or HD testing software from a USB and run hard drive diagnostics
http://www.hirensbootcd.org/usb-booting/