One more variant is described at WindowsSecrets.COM, and includes a registry patch:

• Setting HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\NoWinKeys to 1 disables all Win+x key combinations at once ^{(which is not what the OP wants, but I just mention it for completeness)}
• Navigating to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced\, create/edit DisabledHotkeys as "Expandable String Value", and add the keys you do not want to be triggered along with the "Win" key (e.g. adding 12P would disable Win+1, Win+2, and Win+P)

According to the post, those changes would require a restart (a logoff/logon should be enough for HKEY_CURRENT_USER changes) for the registry to be re-read.

Side-note: I'm not sure whether other apps could re-use hotkeys disabled this way, so take into consideration that this might not be the case.

Other questions here you might wish to lookup:

• Disable (unbind) default Win+Arrows hotkeys to make them usable in other applications
• How can Win+P be disabled in Windows 7?

Update: Just found a post at MSFN explaining how to re-assign those hotkeys to other applications. They used AutoHotkey to accomplish that. This app can be used to disable or re-assign hotkeys, and thus probably gives the most flexible solution. If I understood correctly, you could disable the P key by simply putting #p::return into its config.

This guy didn't find a way, but maybe some of you know more.

Not likely. I have been trying to find a way to prevent Windows Vista+ from hogging hotkeys since they came out.

The fact is, that unlike most Windows hotkeys that can be disabled with the NoWinKeys setting, there are several that are not registered via Windows Explorer. Instead, the higher- (lower-?) level CSRSS registers several hotkeys early in the boot process, so not only can you not register them first, but there is no setting to not use them. These are the keys are specially handled:

Win + P
Win + L
Win + U
Win + G
Win + X
Ctrl + Shift + Esc
Ctrl + Alt + Del

They can be overridden by certain programs like AutoHotkey, but not in the way that you are looking for (allowing programs to register them globally).

Maybe there is some dll/exe we can easily patch. ;-)

That is also quite unlikely. It would require hacking core components of Windows and even if the location where the hotkeys are registered were found and patched, it would mean that you would have to prevent security software from viewing the patch as an infection and make sure to reapply the patch after every Windows update.

You can try the Windows Hotkey Explorer which uses Windows hooks to determine the source of global hotkeys. Unfortunately it only shows these special combos as being reserved by System, meaning that they are loaded by the Windows core. What’s even more interesting with WHE is that it says the same thing for these keys even in Windows XP where they are not used. This implies that they are not actually being read like the other ones, and instead of hard-coded, which unfortuantely means that even with low-level Windows hooks, WHE cannot directly access them. This makes it especially unlikely that any sort of easy patch, driver, etc. can be made to stop them from being bound.

Sadly, the best, most effective solution would be to leave Microsoft feedback and hope they change it in a future update, but that rarely if ever works.

In my case, I simply gave in and changed my XMPlay hotkeys to use the arrow keys on the numeric keypad instead.