Try doing the self-test for the hard drive. It could be a sign of hard drive failure. Just boot to BIOS go under diagnostics then select Primary Hard-drive Self Test. In hp notebooks, we use f10 after turning it on to boot into bios. Ask your computer manufacturer how to boot to BIOS. If you're Hard drive passed the test you might want to try re-installing the operating system. It could be a sign of Windows crashing. If you're Hard drive failed. There you go. You have to replace the hard drive. Hope this helps.