Resetting video "in the dark"

My son's friend has been "adjusting" video settings on his PC (XP Home,
onboard video) and is now in the position where:

- XP Splash screen shows OK
- "Windows sound" is heard at the stage that is normally comes on.

But screen is blank.

Booting into Safe Mode has the same result - it seems that XP is
runnning, but even in Safe Mode, the "adjusted" video settings will not
drive his screen.

We think that XP is loading fine - apart from the lack of screen
display - so can anyone suggest any easy set of keyboard strokes (or
command that we could enter under Start | Run ) that we could use
"blind" to adjust the display values to a different setting?

Or is there any option available from an XP installation CD which would
allow us to change settings without repairing/reloading XP?

The PC does not have an AGP port. I have read a suggestion that
installing a PCI graphics card might see the Plug & Play procedure find
a viewable setting on bootup. How likely is that?

John Geddes
England

<john@starmarkassociates.co.uk> wrote in message
news:1148326925.722709.56430@g10g2000cwb.googlegroups.com...
> My son's friend has been "adjusting" video settings on his PC (XP Home,
> onboard video) and is now in the position where:
>
> - XP Splash screen shows OK
> - "Windows sound" is heard at the stage that is normally comes on.

Do you hear the Power-On Self test (POST) single beep?
This is Important.

>
> But screen is blank.
>
> Booting into Safe Mode has the same result - it seems that XP is
> runnning, but even in Safe Mode, the "adjusted" video settings will not
> drive his screen.
>
> We think that XP is loading fine - apart from the lack of screen
> display - so can anyone suggest any easy set of keyboard strokes (or
> command that we could enter under Start | Run ) that we could use
> "blind" to adjust the display values to a different setting?
>
The screen displays the taskbar? You have access to Start/Run?
If so I suggest a system restore.

> Or is there any option available from an XP installation CD which would
> allow us to change settings without repairing/reloading XP?
>
> The PC does not have an AGP port. I have read a suggestion that
> installing a PCI graphics card might see the Plug & Play procedure find
> a viewable setting on bootup. How likely is that?
>
> John Geddes
> England
>
Have you tried booting from the XP disk and choosing repair?
What settings did he mess with? BIOS?