you need administrative rights to fetch this (be also aware, not this case, of Registry Redirection: search it in my bibliotheca)

perl -MData::Dump -MWin32 -e "
print Win32::IsAdminUser()?qq(ADMIN\n):qq(NOT admin\n); 
use Win32::TieRegistry(Delimiter=>'/'); 
my $idval = $Registry->'HKEY_LOCAL_MACHINE/HARDWARE/DESCRIPTION/System
+/CentralProcessor/0'}; 
dd $idval
"


NOT admin
undef


#launched portableshell.bat as administrator:

perl -MData::Dump -MWin32 -e "
print Win32::IsAdminUser()?qq(ADMIN\n):qq(NOT admin\n); 
use Win32::TieRegistry(Delimiter=>'/'); 
my $idval = $Registry->'HKEY_LOCAL_MACHINE/HARDWARE/DESCRIPTION/System
+/CentralProcessor/0'}; 
dd $idval
"


ADMIN
bless({
  # tied Win32::TieRegistry
  "/Component Information"     => "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0",
  "/Configuration Data"        => pack("H*","ffffffffffffffff000000000
+0000000"),
  "/FeatureSet"                => "0x3D1B3FFF",
  "/Identifier"                => "Intel64 Family 6 Model 94 Stepping 
+3",
  "/Platform Specific Field 1" => "0x00000002",
  "/Previous Update Revision"  => "\0\0\0\0\xA0\0\0\0",
  "/ProcessorNameString"       => "Intel(R) Core(TM) i5-6400 CPU \@ 2.
+70GHz",
  "/Update Revision"           => "\0\0\0\0\xC6\0\0\0",
  "/Update Status"             => "0x00000000",
  "/VendorIdentifier"          => "GenuineIntel",
  "/~MHz"                      => "0x00000A98",
}, "Win32::TieRegistry")
[download]

L*

PS you also have a (not influencing results) double delimiter in /0//Identifier