TSGL: Compaq wont boot

[Ron Grant]

I could sure use some help!

Working on my wife's Compaq S4100NX desktop.
Running (Actually not running) Win XP sp2.

The machine was shut down after running fine. when trying to reboot it will 
show the Compaq flash screen with options of going to the setup bios, or to 
do system restore. After that screen the monitor goes blank and nothing else 
happens. No activity at all. It does not go to the screen where a last known 
configuration is a choice, etc.
I can get to the bios settings.  The system restore that is available will 
wipe all files before restoring the system.

Here's what I have tried so far:

I have repeatedly tried to get to Safe mode by using the F8 key at start up. 
Never happens.

I opened the case and cleaned inside, and unplugged and re-plugged all 
ribbons and power connections and removed and replaced the two memory 
sticks.

No change, so I used a Win 98 start up disk to see if I could boot with 
that.
I ran Scandisk and after a very extensive scanning process, reporting a 
multitude of bad files, etc. Reports of garbled system files and allowing 
scandisk to fix them, I rebooted in hopes of some sort of boot. . . . 
Nothing more than the splash screen mentioned above.

At this point I do not know what to do.  I have one 'Vegas' movie file that 
I would like to save if at all possible.  The rest of the files, I have a 
back up on most of them.

Through the start up disk I can get to a command prompt.  Does anyone know 
what I can do to either get Windows to boot, or to extract that large movie 
file from this computer?

TIA for any advice!

Ron Grant