Decipher error message

Microsoft Windows 98

I have a friend who gets the following message when she
turns on her computer which employs Windows 98:

Out of Range

Hf: 30 KHz - 70 Khz

Uf: 50Hz - 150 Hz

Current Frequency

fh: 74.6 KHz fv: 59Hz


She asked me what this message means, and I told her that
I didn't have the foggiest idea. I have also gotten some
cryptic messages on my computer from time to time but
nothing of this nature. I will appreciate it if somebody
can decipher the meaning of this message for me.

Bob B.
She is overdriving her monitor.

Right-click on the Desktop
Select Properties, then Settings
Click on the Advanced button
Click on the Adapter tab
Nudge the Refresh rate down a step
If she still gets the message, repeat the procedure