I am not from Dell.  Your Windows issue could be due to “in-place upgrade to Windows 11 25H2;”

such upgrade is similar to in place upgrade from 10 to 11 etc and prone to driver issue.  Try a clean install of Windows 11 25H2 by wiping ssd after backing up data. You will get both hdmi and DP working in clean Windows 11 install 

I now have another identical OptiPlex 3060 SFF available, so I was able to test a different system board. I moved the system drives to the other machine and tested the same Windows installation.

Nothing changed — the HDMI monitor is still not detected in Windows.

At this point, I believe this is definitely a Windows issue rather than a hardware problem.

I can only work on this further during the weekend. I will post the results after I try the next steps.

Thanks for the suggestions.

Windows 11 in place upgrade has messed up display driver 

The Windows 11 in-place upgrade to 25H2 was performed only after the HDMI problem had already appeared.

The HDMI output was not working in Windows before the upgrade to 25H2. I upgraded from 23H2 to 25H2 later as part of the troubleshooting, but the problem remained exactly the same.

So the in-place upgrade cannot be the original cause of the problem.

that would suggest the display driver was already messed up in Windows 11 23H2 and a clean 25H2 install would be good step to try.

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Hi

This AI response pretty much re-inforces the other posts (hence the strikethru on the repetition) about corruption, the correct drivers and/or a re-install......

This is a known issue on OptiPlex 3060 SFF units with Intel UHD Graphics 630: Windows often loads the wrong/legacy graphics stack or a corrupted driver, while Linux uses the correct kernel driver and thus sees HDMI.dell+2

Quick fix (most reliable)

Do a clean reinstall of the Intel graphics driver in Windows using DDU, then install the correct Intel DCH driver.dell+2

1) Prepare

1. In Windows, download:

   • Display Driver Uninstaller (DDU): https://www.wagnardsoft.com/display-driver-uninstaller-DDU-

   • Intel Graphics driver for 7th–10th gen (includes UHD 630):
     https://www.intel.com/content/www/us/en/download/776137/intel-7th-10th-gen-processor-graphics-windows.html
     (get the latest Windows 10/11 DCH driver; Dell’s own driver page for OptiPlex 3060 also has a matching Intel UHD 630 driver if you prefer OEM).dell+2

2. Disconnect from the internet (unplug Ethernet / turn off Wi‑Fi) so Windows Update doesn’t auto‑install another driver mid‑process.dell+1

2) Clean out the existing Intel graphics driver

1. Run DDU.

2. Select:

   • Device type: GPU

   • Vendor: Intel

3. Choose Clean and restart (let it reboot into Safe Mode if it asks).dell

After reboot, you should be on the Microsoft basic display adapter.

3) Install the correct Intel driver

1. With the network still disconnected, run the Intel graphics driver you downloaded (e.g. gfx_win_101.xxxx.exe).

2. Install, let it reboot when prompted.

3. After reboot, confirm in Device Manager → Display adapters → Intel(R) UHD Graphics 630 → Driver tab that the version matches the one you just installed.dell

4. Reconnect to the internet.

4) Enable HDMI in Windows

1. Connect the HDMI monitor.

2. Press Win + P and choose Extend or Duplicate.

3. If it still doesn’t appear:

   • Open Settings → System → Display and click Detect.

   • Open Intel Graphics Command Center (or Intel Control Panel) and ensure the HDMI display is enabled / set as primary if needed.dell

This sequence fixes the “HDMI works in Linux but not Windows” symptom on many 3060 SFF boxes.dell+1

If HDMI still missing in Windows

Try these in order:

A) Force Windows to re-detect the display

• In Device Manager:

  • Expand Monitors, right‑click any listed monitor → Uninstall device.

  • Expand Display adapters, right‑click Intel(R) UHD Graphics 630 → Uninstall device, tick Delete the driver software for this device, then reboot.

  • After reboot, reinstall the Intel driver as above.community.intel+1

B) Disable Fast Startup and tweak power settings

Sometimes HDMI dies after sleep/fast startup:

1. Control Panel → Power Options → Choose what the power buttons do.

2. Click Change settings that are currently unavailable.

3. Uncheck Turn on fast startup (recommended) → Save.

4. In your active power plan → Change plan settings → set Turn off the display to Never temporarily for testing.dell

Reboot and test HDMI again.

C) BIOS / firmware checks

1. Reboot, press F2 for BIOS.

2. Load Defaults / Optimal Defaults, save & exit.

3. Ensure:

   • Onboard Devices → Video / Integrated Graphics is Enabled.

   • No odd multi‑display lockouts (some BIOSes have “Primary Display” options; set to Auto or IGFX).

4. If available, update the BIOS and Intel ME / chipset drivers from Dell’s OptiPlex 3060 support page.dell+1

D) Test with another cable / monitor / port

• Try a different HDMI cable and monitor/TV.

• If you have a DP→HDMI adapter, test that path; if DP→HDMI works but native HDMI doesn’t, that points more strongly to a Windows driver/EDID issue rather than hardware.

We hope you had an opportunity to perform the troubleshooting steps and resolve the issue.

Update:

I restored my old Windows system image from 30 March 2025. At the time this image was created, both monitors were working in Windows.

After restoring the image, the HDMI monitor was still missing in Windows.

I then restored my current Windows image and performed a completely clean Intel graphics driver removal using DDU. I installed Intel graphics driver 31.0.101.2141 with the network disconnected.

There was no change: Windows still detects only the DisplayPort monitor and the HDMI monitor remains unavailable.

For completeness, I repeated the entire DDU + 31.0.101.2141 procedure a second time after restoring the image again. The result was exactly the same.

So far:

• Old Windows image (30 March 2025): HDMI still missing after restoration

• DDU + Intel 31.0.101.2141: no effect

• DDU + Intel 31.0.101.2141 repeated a second time: no effect

The next test I am considering is a completely clean Windows installation on a separate drive, then testing the same two monitors on both of my identical OptiPlex 3060 SFF systems.