I have an old Dell Inspiron and when I boot up it says it cannot locate an operating system. I got into BIOS and look at startup and it says internal HDD on startup. Bios battery or hdd do you think?
Most likely either a failing hard drive or just errors on it. What brand is the hard drive? You'll have to download the drive makers disk diagnostic program and do a full test on it. Are you sure there is an OS on it?