There are several reasons why a program may not be skinned by WindowBlinds. A few programs are protected by the operating system from skinning – for example, the DOS prompt or cmd windows in early versions of Windows. 16-bit applications are not skinned for a similar reason.
Some applications are excluded from skinning because they skin themselves – there’s no point trying to draw the windows of an app that draws them themselves. Then there are the applications that cause problems when skinned. Usually, this is because the programmer has done something non-standard or has made an incorrect assumption about, say, the sizes of windows. This can mean that windows do not display correctly, resize incorrectly, or in the worst cases can cause a freeze or crash. If no workaround can be found the application has to be excluded.
You may find that certain exclusions are not needed – as newer versions come out, bugs may be fixed, or the problem may only be a problem on a previous version of Windows. If you wish, you can try removing exclusions from the WindowBlinds settings dialog, Per Application section.
You can also add exclusions there – if you find an app that needs excluding, tell us here and if it’s found to be a general problem it’ll get put on the main exclusion list.
You can also post about it here as well as see what applications are being reported as having an issue: https://forums.stardock.com/415220/page/1