Sysinternals' Portmon: Error 2

In Windows Explorer, right click on portmon.exe --> select Properties --> click the Compatibility tab, and Run in Windows XP compatibility mode. It works fine like that in Windows 7 64-bit.

Sysinternals' Portmon works only on 32-bit versions of Windows. It does not support 64-bit (probably its driver is not signed).

From the Portmon homepage:

• Runs on:
  • Client: Windows XP (32-bit) and higher (32-bit).
  • Server: Windows Server 2003 (32-bit) and higher (32-bit).