Disconect any external device (like usb sticks, etc) and try again
You can try boot from cd (change boot order in bios to set cd rom first) and press R for recovery console.
Type 1, hit enter, type password or just hit enter if U don't have one, and type
chkdsk /r /f and hit enter. Let it check.
You can try setting your bios to default. (f2 or del at startup)
You can try Hirren boot cd to scan and other stuffshttp://www.tomsguide.com/us/download/Hiren-s-BootCD,0301-32451.html
Some PC's have their own tests at startup, (like hard drive test, memory test) .See if yours has that or not.