update - been too dizzy this morning :-(

Turn the eval block into a string eval and wrap it in a BEGIN block. This way the eval is executed and the module loaded before the call to Win32::DriveInfo::DriveSpace is even compiled. I can't test, because I don't have a Windows box at hand.

Put this at the very beginning of your script:

BEGIN {
    if ($^O =~ /^(MS)?Win/) {
        eval "use Win32::DriveInfo";
        die $@ if $@;
    }
}
[download]

What happens if you turn the eval block into a string eval? I can't test, because I don't have a Windows box at hand.

if ( $^O =~ /^(MS)?Win/ )
{
    eval "use Win32::DriveInfo";

    $TotalNumberOfFreeBytes = (Win32::DriveInfo::DriveSpace('c:'))[6];
    $TotalNumberOfBytes = (Win32::DriveInfo::DriveSpace('c:'))[5];

    print "This is $^O \n";
    print "Total Free: $TotalNumberOfFreeBytes\tTotal size: $TotalNumb
+erOfBytes\n";
    print $@,"\ndone!";
}
elsif ( $^O =~ /^linux/ )
{
    print "This is Linux OS!!!\n";
}
[download]

--shmem

update: changed "require" to "use" in the string eval. Small negligence after copy & paste.

_($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}