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"
}
[download]

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";
[download]

It seems there are work-a-rounds for the problem with 64bits registry

What is your environment?

I ask, because I have the 64 bit version of ActiveState Perl 5.16.2 installed on Win7 x64 and Win2012 x64 and the code I posted just works, no fixes or workarounds necessary. (and no, the 64 bit version of Windows does not have multiple registries, that would actually be insane. What it does is store entries from 32 bit apps in alternate subsections of the registry, such as the Wow6432Node folder)

Sorry for late reply

I use Strawberry Perl 5.20 32bits

Windows server 2008