An HDR desktop must map ordinary SDR content into its output environment. The operating system’s SDR brightness balance, display settings and app behaviour can therefore change how an SDR video looks. This is separate from whether the video itself contains HDR information.
Identify the content type
Do not assume a video becomes HDR because the desktop’s HDR toggle is enabled. Check the source information when available and compare a known SDR clip. A streaming player can show SDR within an HDR output, so the monitor’s HDR indication alone does not prove the programme’s original dynamic range.
Use the correct display settings
On Windows, select the intended display in the system’s display settings before adjusting HDR-related controls. Multi-monitor systems can have different capabilities and settings on each screen. Consult the current Microsoft instructions for the installed version rather than following a menu path from an older screenshot without checking its labels.
Compare without changing everything
Record the existing settings, adjust the relevant SDR content brightness balance if available, and replay the same clip. Keep the monitor’s picture preset stable during the comparison. If one app differs substantially from another, note both versions and the display configuration; the problem may concern that app’s rendering path rather than the media account.