ASM-00203 and Windows 2008 R2

I was fighting right now with my favorite Operating System and ASM :-) I just installed Oracle Grid Infrastructure on a standalone Windows 2008 R2 server (successfully) and wanted to stamp some disks with the tool asmtoolg.exe. After I started the asmtoolg from a command prompt, I receive immediately an error message: ASM-00203: No valid devices found Cool :-) Oracle Metalink brings back following result: After a little bit playing, I found...