Thanks for extra info

It seems there are work-a-rounds for the problem with 64bits registry, it is located here it lies in access rights

I managed to create a scrip to retrieve all subkeys, it's this

use Win32::TieRegistry( Delimiter=>"#", ArrayValues=>0 );
my $pound = $Registry->Delimiter("/");

# This syntax passes the HEX flag to access the 64 bit registry
$BaseKey = $Registry->Open("HKEY_CLASSES_ROOT/Installer/Patches", {Acc
+ess=> 0x20019|0x0100});
foreach $key (keys %$BaseKey)
{ print"$key: " . $BaseKey->{"$key"} . "\n"
}
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update

Found a way to retrieve all the PackageName value from: HKEY_CLASSES_ROOT/Installer/Patches/XXXXXXX/SourceList
Where XXXXXX = $key from example above

$SubbyKey = $Registry->Open("HKEY_CLASSES_ROOT/Installer/Patches/".$ke
+y."SourceList/", {Access=> 0x20019|0x0100});
print $SubbyKey->{'PackageName'}."\n";
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