Just started getting this message so did quite a bit of research. First called HP, got the recovery disks but did not fix problems (mid-way through recovery the system would restart and again, "operating system not found" on restart. Called HP again, they said hard drive was failing so I bought a new one, again no success. Called HP again and they told me for $50 they could walk me through some diagnostics but I probably needed a new motherboard ($350 plus the $50 call).
Started internet research, got a lot of info regarding similar problems where neither replacing the hard drive or motherboard did much good, due to possible overheating of CPU or video card. A lot of comments about an expensive paperweight, etc.
Decided to blow out the vents and try again, and the entire recovery and reinstall of Vista ran to completion. No noticeable overheating of the bottom of the laptop. Got excited as I set up personal settings in Vista this morning, did final restart and got "operating system not found".
Bummed, I did a couple of final checks with nothing in the CD drive and saw one thing of interest - in the boot drive menu, two options are available:
2. CD drive
3. Notebook hard drive
Note there is no option 1 listed. Even after going to the setup menu and pressing F9 to reset defaults, still no option 1. Then, when I selected option 3 from the boot options, the HP started right up.
So, long story I know, but is there a way on this laptop to reset the #1 drive option to be the hard drive? If so, is this a long term fix or will the HP "lose" the #1 option again due to a more sinister problem. Any suggestions/comments will be appreciated. I have replaced this laptop already so the real reason I am after a solution is sheer stubbornness.