use strict;
use Win32::Daemon;

# Tell the OS to start processing the service...
Win32::Daemon::StartService();

# Wait until the service manager is ready for us to continue...
while(SERVICE_START_PENDING != Win32::Daemon::State()) {
   sleep(1);
}

# Now let the service manager know that we are running...
Win32::Daemon::State( SERVICE_RUNNING );

# Okay, go ahead and process stuff...
while(1) {
   # delete all *.tmp files at c:\temp
   unlink( glob( "c:\\temp\\*.tmp" ) ); 
   last unless keep_alive();
   sleep(5); # and wait
   last unless keep_alive();
}

# Tell the OS that the service is terminating...
Win32::Daemon::StopService();

sub keep_alive {
   my $msg = Wun32::Daemon::QueryLastMessage();
   return (
      $msg != SERVICE_STOP_PENDING and
      $msg != SERVICE_CONTROL_SHUTDOWN
   );
}
[download]

The only other thing to note is if you are going to have it run as a service, make sure the service has proper permissions to delete files from the hard drive. LocalSystem may not cut it.

use strict;
use warnings;
no warnings 'uninitialized';

use Win32::Daemon::Simple
    Service => 'DelService',
    Name => 'SERVICE NAME',
    Version => 'x.x',
    Info => {
        display =>  'SERVICEDISPLAYNAME',
        description => 'SERVICEDESCRIPTION',
#        user    =>  '',
#        pwd     =>  '',
        interactive => 0,
    },
    Params => { # the default parameters
        Interval => 5*(1/60), # it's in minutes!
        LogFile => "ServiceName.log",
        Directory => 'c:\the\directory\\',
    };

ServiceLoop(\&doTheJob);

Log("Going down");
exit;

sub doTheJob {
    opendir my $DIR, DIRECTORY
        or die qq{Can't read the contents of "} . DIRECTORY . qq{" !\n
+};
    while (my $file = readdir $DIR) {
        next if -d (DIRECTORY . '/' . $file); # don't try to unlink di
+rectories
        # you can add some filtering here if you do not want to delete
+ everything
        unlink (DIRECTORY . '/' . $file);
    }
    closedir $DIR;
}
[download]

This is a complete program! Able to install and deinstall itself as a service, allowing you to change the parameters stored in the Windows registry from the command prompt, etc. etc. Check out Win32::Daemon::Simple on CPAN or on my page.