Not very up on Windows, but it seems that system is passing the request to Windows where the space separated elements of the path are being interpreted as individual parameters. If you look at the documentation for system, it suggests the following would work:

system($browser, $Path);
[download]

The elephant that's been mentioned only implicitly is 'doze-style quoting.'

Sorry, this illustration (which presents two ways of working with Win32) is a bit on the long side but here goes, anyway...

#!/usr/bin/perl
use strict;
use warnings;
use 5.018;

# #1107536

my $program="D:\\GnuWin32\\bin\\ls.exe";
print "$program\n";
runit ($program);

sub runit 
{
  system ("$program");
  if ($? == -1) {
     print "failed to execute: $!\n";
  }
  say "\n\t DEBUG: reached the end of sub runit at Ln23";
  sleep 1;
}

say "\n Done with first sub, back in main. \n";

my $path = 'D:/GnuWin32/bin/';
my $pgm="ls.exe";
my $cmd ="$path" . "$pgm";

runit2 ($cmd);

sub runit2 
{
  say "\n\tEntering runit2\n";
  sleep 3;
  my ($cmd_in_sub) = @_;
  say "\n\t DEBUG: $cmd_in_sub\n";
  system ("$cmd_in_sub");
  if ($?) {
     print "failed to execute: $!\n";
  }
}

say "\n Done with second sub ";
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Execution:

D:\>D:\_Perl_\PMonks\1107536NON-GUI.pl d:\_wo
D:\GnuWin32\bin\ls.exe

..                    TestFiles
Connexions           tbos.css
CPM-ZCPR              ViennaProtocol.txt
created_psp_files     WinSHAetc

         DEBUG: reached the end of sub runit at Ln23

 Done with first sub, back in main.


        Entering runit2


         DEBUG: D:/GnuWin32/bin/ls.exe

...                   TestFiles
Connexions           tbos.css
CPM-ZCPR              ViennaProtocol.txt
created_psp_files     WinSHAetc....

 Done with second sub

D:\>
[download]

M$Win mistreats (file and/or dir)_names_with_spaces unless the whole Path/Program_name match is double-quoted.

NB: This also works to invoke a Windows GUI program, such as Chrome or Beyond Compare.

Updated: by removing extraneous code; adding note

In addition to the multi-argument system call, you could instead quote the browser.

system( qq("$browser" "$Path") );
[download]

Wherever available, you should use LIST-style forms of command launching functions. For example, prefer system("rm", "-rf", @temp_directories) over system("rm -rf @unneeded"). The same goes for pipe-open, exec and so on.

This is because when Perl encounters a command which consists of a single string containing so called special characters it passes the whole string to the shell. And modern filesystems allow spaces in file names which are not getting escaped, and this is where your command breaks. Some filesystems even allow glob characters (like * [ ]). Even more fun: imagine creating a file called -rf ~ and trying to remove it by system("rm $filename").

Bad news: list form of open is not supported on Windows. Good news: list form of open2 is. And so is high-level IPC::Run (but I got some problems with binary files transferred via pipe when I used this module).