After reading holli's observation that SystemInfo uses TieRegistry, I took look at the source for SystemInfo. The following bit at the top is lifted almost verbatim from SystemInfo:

use strict;
use warnings;

use Win32::TieRegistry qw(:KEY_);

$Registry->Delimiter("/");
my $procinfo = $Registry->Open(
                "HKEY_LOCAL_MACHINE/HARDWARE/DESCRIPTION/System/Centra
+lProcessor/0",
                { Access => KEY_READ() }
                   );

PrintHash($procinfo);

sub PrintHash
{
    my ($hashref, $indent) = @_;
    my %hash = %{$hashref};
    $indent += 2;

    my $maxsize = 0;
    foreach my $key (keys %hash)
    { 
        $maxsize = length $key if (length $key > $maxsize);
    }
    
    foreach my $key (sort keys %hash)
    {
        printf "%*sKey: %-*s Value: %s\n", $indent, "", $maxsize, $key
+, $hash{$key};
        if (ref $hash{$key} eq 'ARRAY') { PrintArray($hash{$key}, $ind
+ent); }
        if (ref $hash{$key} eq 'HASH')  { PrintHash($hash{$key}, $inde
+nt); }
    }
}

sub PrintArray
{
    my ($array, $indent) = @_;
    my @arr = @{$array};
    $indent += 2;
    my $cnt = 0;
    foreach my $elem (@arr)
    {
        printf("%*s%2d. %s\n", $indent, "", $cnt, $elem);
        if (ref $elem eq 'ARRAY') { PrintArray($elem, $indent); }
        if (ref $elem eq 'HASH')  { PrintHash($elem, $indent); }
        ++$cnt;
    }
}
[download]

Here is the result:

  Key: /Component Information     Value:
  Key: /Configuration Data        Value:         
  Key: /FeatureSet                Value: 0x3D1B3FFF
  Key: /Identifier                Value: Intel64 Family 6 Model 60 Ste
+pping 3
  Key: /Platform Specific Field 1 Value: 0x00000020
  Key: /Previous Update Revision  Value:     
  Key: /ProcessorNameString       Value: Intel(R) Core(TM) i7-4700HQ C
+PU @ 2.40GHz
  Key: /Update Revision           Value:     %
  Key: /Update Status             Value: 0x00000000
  Key: /VendorIdentifier          Value: GenuineIntel
  Key: /~MHz                      Value: 0x0000095A
[download]

Apparently "Access => KEY_READ()" indicates that read-only access is requested, which makes everything good.

Thanks for the responses. This issue is resolved