NS_E_WMP_BMP_TOPDOWN_DIB_UNSUPPORTED (0XC00D102F): Fix Top-Down DIB Error

Quick answer: Windows Media Player can't render BMP files that store pixel rows from top to bottom. Convert the file to a bottom-up BMP, PNG, or JPEG, or play it in a viewer that actually supports top-down bitmaps.

You're probably seeing 0XC00D102F — which Windows surfaces as NS_E_WMP_BMP_TOPDOWN_DIB_UNSUPPORTED — when you drop a BMP into a WMP playlist or slideshow and hit play. WMP's codec chain reads the DIB header's height field, sees a negative value, and bails out. Negative height in a BITMAPINFOHEADER means the rows are written top-down. Plenty of modern scanners, phone exports, and screenshot tools write BMPs that way because it matches how most people think about image coordinates. Microsoft never bothered to teach WMP the trick, so you get the error instead of the picture.

I hit this constantly with Fujitsu ScanSnap output and some older Canon utility exports. The file opens fine in Paint and Paint.NET, which is why the error feels so random. It isn't. It's a real format quirk, and the fix is straightforward once you know where to look.

Fix 1: Convert the BMP to a supported format

The real fix is to stop feeding WMP a top-down DIB. Convert the file to PNG or JPEG and WMP will play it without complaint.

1. Right-click the BMP file and choose Open with > Paint.
2. Click File > Save as, pick PNG or JPEG, and save it next to the original.
3. Delete the old BMP from your playlist or slideshow folder so WMP stops tripping over it.
4. Re-add the converted file and hit play.

If you've got hundreds of these (a scanned photo archive, say), don't do them one at a time. Open a Command Prompt in the folder and run ImageMagick:

magick mogrify -format png *.bmp

That drops a PNG copy of every BMP in the directory in about the time it takes to make coffee. Swap the format for jpg if you'd rather keep file sizes down.

Fix 2: Convert to a bottom-up BMP

If a downstream system actually requires BMP (some legacy print pipelines do), you can rewrite the file with a positive height value. Paint.NET does this on save by default. Open the file, hit Ctrl+Shift+S, choose BMP, and save. The default BMP encoder writes bottom-up.

You can also flip the header yourself with a hex editor if you're feeling brave. Open the file, find the DIB header (starts 14 bytes in, signature 42 4D for "BM"). The height field is a 4-byte little-endian signed integer. Make it positive, then reverse the row order in the pixel data. That second part is why I don't recommend hand-editing unless you have exactly one file and a lot of patience.

Fix 3: Use a viewer that supports top-down DIBs

WMP is not a photo viewer. It's a media player that loosely tolerates images for slideshow use. If you just need to look at the file, open it in Photos, IrfanView, XnView, or VLC. All four handle top-down BMPs without a fuss. IrfanView is my go-to because it batch-converts from the same window you view from.

Fix 4: Reset the WMP library and file associations

Occasionally the error sticks around even after you've converted the offending file, because WMP is holding a stale reference in its library database. Clear it:

1. Close WMP completely. Check Task Manager to be sure.
2. Open Run (Win+R) and paste:
   %LOCALAPPDATA%\Microsoft\Media Player
3. Rename the folder to Media Player.old.
4. Relaunch WMP. It rebuilds the library on next scan.

On Windows 7 or 8.1, the path is %LOCALAPPDATA%\Microsoft\Windows Media Player instead. Same idea either way.

Alternative fixes if none of the above works

• Update your graphics driver. I've seen outdated Intel HD 4000 drivers on Windows 10 cause WMP image codec weirdness that looked exactly like this error. Grab the latest from Intel, AMD, or NVIDIA directly — Windows Update lags months behind.
• Re-register the WMP codec DLLs. Open an admin Command Prompt and run:
  regsvr32 wmp.dll
regsvr32 wmpshell.dll
  Reboot after.
• Install the K-Lite Codec Pack (Standard). It replaces WMP's image decode path with ffmpeg-based filters that don't care about DIB orientation. Heavy-handed, but it works.
• Switch to VLC for slideshows. VLC handles BMP, top-down or not, and it's a better slideshow tool than WMP ever was.

Prevention tip

Stop letting scanners and screenshot tools dump raw BMP into your media folders. Most of them have an output format setting buried in preferences — set it to PNG once and you'll never see 0XC00D102F again. If you're stuck with a tool that only writes BMP, add a nightly mogrify job or a PowerShell one-liner to convert new files automatically. Ten minutes of setup saves you from debugging this again six months from now.

Bottom line: the error is WMP's fault, not yours. Convert the file, and move on.