I have an HP ZR24w monitor connected via HDMI input to a newer custom machine running Win7, and via VGA input to an older Micron machine running Win98SE. I use the monitor's "source" setting to choose which system is displayed (a KVM switch controls keyboard/mouse input). This monitor has a 60Hz (or 59Hz, depending on where you look) refresh rate. When the Win98 machine is booting, the monitor reports "Signal Out of Range". I don't know if it's the resolution or the refresh rate that's at fault. Regardless, once Win98 starts, the video signal it produces is within range and everything's fine. So if I want to use Win98 I'm good to go.

But if I switch Win98 to DOS mode (via Restart in MS-DOS Mode), the signal remains out of range and nothing appears on the monitor. Ordinarily, I don't use DOS so this hasn't caused me a problem.

But now I'd like to change the older machine to dual boot WinXP and Win98. I know from prior experience that the boot menu through which I choose the OS at boot-up will be displayed during that "signal out of range" period. Obviously, I can't use a dual boot system if I can't see the boot menu. :-)

Is it possible to configure the old Micron machine to use a video mode during boot (and in DOS mode) that this monitor can display?

  • 6
    Dos text mode uses 720x400 resolution at 70 Hz vertical refresh rate. Checking your monitor's EDID data on edid.tv it seems it's not capable of anything non-60Hz
    – Vlad
    Jul 13, 2021 at 17:40
  • That's pretty much what I suspected. So it's not possible to change the DOS text mode to something else (that is, to change the video mode used by DOS)?
    – Javic
    Jul 13, 2021 at 18:28
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    +1 for what Vlad said. Here's a direct link to the monitor's info on edid.tv. That data matches the manufacturer's specifications. Jul 13, 2021 at 18:29
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    @Javic some cards drivers allowed to tweak settings, but I believe those are very few, and tweaking is limited to windows only. You can assume timings are hardcoded in the VGA rom, and won't survive reboot. Even if you find some resident program that would trap video mode initialization, those will be active only after the dos is booted (you won't see any POST messages). And many games would just directly program VGA registers, bringing vertical refresh back to 70 Hz. Only well-behaved program (using int 10h) would run in 60 Hz, and likely would have distorted aspect because of changed timings
    – Vlad
    Jul 13, 2021 at 18:51
  • 3
    I believe NTLDR’s boot menu displays in graphical mode whenever it can, so you may avoid this particular issue. If it doesn’t, you can try installing GRUB4DOS as your boot loader instead. As for how to change the refresh rate under DOS, maybe this answer will help. Jul 14, 2021 at 15:26

2 Answers 2


The main specifications indicate that the ZR24w only supports 60 Hz signals (59.9 – 60.1 Hz) and "text mode" is listed as 640×480. However, in the list of recognized modes in the monitor's manual (p. 37) all the modes are 60 Hz except for:

Preset Pixel Format Horz Freq (kHz) Vert Freq (Hz)
2 720 × 400 31.469 70.087

Given the conflicting specifications in different places, this may be a typo.

I would try using the VGA input since my impression from skimming through the manual is that it does more auto-configuration (and has more tweaking options) on the analog input than the digital ones. The manual also states that one can manually add additional modes but unfortunately doesn't say how to do so. The "Mode Display" option (p. 23) should tell you the current signal's characteristics.

  • Thanks for mentioning the manual! It never occurred to me to go look for one although with that hint I find I already had it on the CD that came with the monitor. Yes, I see on pg. 37 it says "...you may need to readjust the parameters...by using the on-screen display. Your changes can be made to any or all of these modes and saved in memory." But I see no obvious way in the OSD to do what I apparently need to do: change the refresh rate (for any mode). I'll spend more time with it though, and maybe fire off an email to HP tech support. Will post back here if I learn anything new.
    – Javic
    Jul 13, 2021 at 21:59
  • VGA sounds like a good idea Jul 15, 2021 at 7:40

Tech support was useless. They directed me to some team supporting something called "Project Z" or "System Z" or some such thing. I got no response to my inquiry except an email saying the issue had been closed. However, I eventually found instructions explaining how to use HP Display Assistant (a separate utility) to create user profiles. Unfortunately, the utility offers no setting for refresh rate, so it looks like I'm SOL.

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