(Windows) Descriptive error message if no serial port is connected

bin/FIJI/Utils.pm

@@ -190,12 +190,17 @@ sub get_uart_devs {
     my $choices = [];
     my @s;
     if ($^O eq "MSWin32") {
-        my $reg = new Win32::TieRegistry("LMachine\\Hardware\\DEVICEMAP\\SERIALCOMM\\",{Access=>Win32::TieRegistry::KEY_READ(),Delimiter=>"\\"});
+        my $reg = new Win32::TieRegistry("LMachine\\Hardware\\DEVICEMAP\\",{Access=>Win32::TieRegistry::KEY_READ(),Delimiter=>"\\"});
         if (!defined $reg) {
             $logger->error("Can't access registry key: $^E");
         } else {
-            foreach my $port ($reg->ValueNames) {
-                push(@s, $reg->GetValue($port));
+            my $serialcomm = $reg->Open("SERIALCOMM\\");
+            if (!defined $serialcomm) {
+                $logger->error("No serial ports found: $^E");
+            } else {
+                foreach my $port ($serialcomm->ValueNames) {
+                    push(@s, $serialcomm->GetValue($port));
+                }
             }
         }
     } elsif ($^O eq "cygwin") {