I don't recall dos liking long names or spaces in them, so here goes, tried and true:

my $file = 'd:/My Documents/xxxl.html';
   $file = Win32::GetShortPathName("$file");

   system("start $file");

# the above opens $file in the default browser or currently open brows
+er

# the below opens $file in a new copy of iexplore

my $file = 'd:/My Documents/xxxl.html';
my $browser = 'c:/Program Files/Internet Explorer/iexplore.exe';
   $browser = Win32::GetShortPathName("$browser");

system("$browser $file");

# or system("start $browser $file");
[download]

UPDATE:
i also tried lolindraths method, and it'll work assuming you have a short pathname(8.3 format or something). Start works equally as well:) my $Result = `start d:\\MyDocu~1\\xxxl.html`;

"cRaZy is co01, but sometimes cRaZy is cRaZy".
                                                      - crazyinsomniac