use strict;
use Win32::TieRegistry ( Delimiter=>"/", ArrayValues=>0 );
#snapshot registry before install
my $LmRegBefore = $Registry->{"LMachine/Software/"};

#Run the installation program - much harder in real life, but this is a test script :)
my $install='path to install to run';
system($install);

#Flush the reg subkey
my $r=$Registry->{"LMachine/Software/"}->Flush();
print ("Flushing LMachine[$r]");

#snapshot registry after install
my $LmRegAfter = $Registry->{"LMachine/Software/"};

registryChanges($LmRegBefore,$LmRegAfter);

#############
sub registryChanges{
	my $regBefore=shift;
	my $regAfter=shift;
	foreach my $key (keys(%{$regAfter})){
		if(!defined $regBefore->{$key}){
			my $val=$regAfter->{$key};
			$change{$key}=$val;
			print "registryChanges[$key]=[$val]\n";
        	}
    	}
	}