Cut and paste the following into a file with a .reg extension (e.g. Disable Logo Key.reg).

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlKeyboard Layout]
"Scancode Map"=hex:00,00,00,00,00,00,00,00,03,00,00,00,00,00,5b,e0,00,00,5c,e0,
00,00,00,00

Right click on the file and choose Merge to add it to your Windows registry and disable the key.

Do the same (in another file, e.g Enable Logo Key.reg) for the following should you wish to re-enable the key:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlKeyboard Layout]
"Scancode Map"=-