I have an HP G61 that is hanging itself up right after the HP screen before windows starts. The esc to startup works, hard drive tests good, memory as well. so computer seems to be functioning, Just no OS, to speak of. F11 doesn't work, nor F8. but everything for the basic computer works fine. So, its power up, HP logo page 3 seconds or so, then black until a hard boot shut down. Can anyone assist me thank you.