Laptop Help!!!

[lsamorph2]

I have a Compaq Presario 1692 that was giving to me. It worked fine when I got it. But I did not used it for almost a year. When I tried to power it up it told me "operating system not found." The hard drive is working fine. I even tried another compatible hd and it work fined, but after a few hours it gave me the same message operating system not found. Any ideas what might be wrong. Any help will be appreciated. Thanks

 

[Captain4]

Might be a dead battery on the motherboard.

 

[LiLithTecH]

More than likely the CMOS battery needs replacing.
With a bad battery, it no longer retains the CMOS info
after you power down.