How do I find out which programs have registered global hotkeys in Windows 10?

My media hotkeys (play, pause, next, etc.) have been stolen by an unknown process. How do I find a list of which global hotkeys are registered to which program in Windows 10? There are a few programs out there that do this but they only work up to Windows 7 and screw up on Windows 8+.

Answer

Hotkeys and multimedia keys may be overridden by hardware or drivers(unlikely), by a running program, or by system setting.

These three are distinct, and need different ways to check and solve.

Hardware

Your keyboard may have different modes, usually selectable with FN key combination. Some smart keyboards are configurable through a windows utility. See your keyboard documentation.

Running programs

Although this approach is a bit brutal, I suggest launching the task manager and terminating all processes except system ones like: svchost, lsass, csrss, smss, services, userinit, dwm, winlogon, explorer.

If that helped, reboot and try terminating them one by one to see which one causes problems. You can disable startup of offending process through msconfig or SysInternals autoruns programs.

System settings

Press windows Start button, type 'regedit' and browse to HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer

Delete registry key ("folder") named AppKey if it exists.

Now browse to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\AppKey and do not delete it.

There are few subkeys (subfolders) that define which program is started when a multimedia key is pressed.

Below are the defaults for windows 7, yours should be similar:

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\AppKey]

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\AppKey\15]
"Association"="mailto"

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\AppKey\16]
"Association"=".cda"

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\AppKey\17]
"ShellExecute"="::{20D04FE0-3AEA-1069-A2D8-08002B30309D}"

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\AppKey\18]
"ShellExecute"="calc.exe"

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\AppKey\7]
"Association"="http"

To assign a key to a program of your choice, delete any values under appropriate registry key, and create a new string (REG_SZ) value named ShellExecute and a full path to a program of your choice as a value, such as c:\vlc\vlc.exe

If there is no key with the number you need (see below), just create one.

Here is a list of known multimedia keys and their corresponding numbers under Appkey\

1   Back (Internet browser) 
2   Forward (Internet browser) 
3   Refresh (Internet browser)
4   Stop (Internet browser)
5   Search
6   Favourites 
7   Web Home
8   Mute volume 
15  Mail 
16  Media 
17  My Computer 
18  Calculator 
24  Mute microphone 
25  Lower microphone volume 
26  Raise microphone volume
27  Help 
28  Find 
29  New
30  Open
31  Close 
32  Save
33  Print
34  Undo
35  Redo
36  Copy 
37  Cut 
38  Paste
39  Reply
40  Forward (mail) 
41  Send
42  Spelling checker
43  Toggle dictation and command/control
44  Toggle microphone
45  Corrections 

(Aforementioned list was copied from https://groups.google.com/forum/#!msg/microsoft.public.fr.windowsxp/zZolgM6PC4o/sRJv2NtrB-8J (in French) )

The settings should work after reboot.

Desktop shortcuts

It may be possible to assign the hotkeys you need to a shortcut on windows desktop, start menu, quick launch panel, or pinned to the task bar.

Searching through those could be a pain, instead you may want to copy following text in a new text file, replace c:\ in first line with your user home directory path such as c:\Users\jwhite\, save under a name Script.vbs and run it.

Const rootdir = "c:\"

Set fso = CreateObject("Scripting.FileSystemObject")
Set wshell = CreateObject("WScript.Shell")

logname="test.txt"
Set logfile = fso.CreateTextFile(logname,True)
logfile.Write "Searching for shortcuts with hotkeys" & vbCrLf

recursedirs( fso.GetFolder(rootdir) )

logfile.Write "Done searching" & vbCrLf
logfile.Close

Sub recursedirs(dir)
    If trylistdir(dir) Then
        For Each subdir In dir.SubFolders
             recursedirs subdir
        Next

        For Each file In dir.Files
            extn = fso.GetExtensionName(file.Path)
            if LCase(extn) = "lnk" Then
               check(file.Path)
            end if
        Next
    End If
End Sub

Function trylistdir(dir)
  On Error Resume Next
  trylistdir = (dir.SubFolders.Count + dir.Files.Count >= 0)
End Function

Sub check(fname)

    Set lnk = wshell.CreateShortcut(fname)
    hk = lnk.Hotkey
    if (hk<>"") then
       logfile.Write fname & " : " & hk & vbCrLf
    end if

End Sub

After a few minutes it should create a file named test.txt in the same folder as script itself with contents such as:

Searching for shortcuts with hotkeys
C:\test\test01.lnk : Alt+Ctrl+Z
C:\test\test02.lnk : Alt+Ctrl+Shift+E
Done searching

Software

AFAIK, Windows Hotkey Explorer software worked by pressing every hotkey it could, and then attempting to intercept whatever got called as a result. I believe as of Windows 8 and higher it is not possible to intercept hotkeys that way anymore, therefore this method no longer works, so there may be no such a software possible.

I believe asking for software recommendation may not be appropriate for SuperUser.com anyway, instead you may want to upvote following question on website dedicated for that: https://softwarerecs.stackexchange.com/questions/33669/tool-to-list-all-current-windows-hotkeys