To expand on anonymonks terseness, you need to make sure that the file is read and written as binary to avoid newline translations. "pushing raw" translates to prefixing the encoding with ':raw'. The following works (copies a utf16le file with futzing with it) for me, but without the ':raw's, I see the same symptoms you describe. 

#! perl -slw
use strict;
use PerlIO::encoding;

open IN, '<:raw:encoding(UTF-16LE)', $ARGV[ 0 ];
open OUT, '>:raw:encoding(UTF-16LE)', $ARGV[ 0 ] . '.modified';
print OUT <IN>;

close $_ for *IN, *OUT;

[download]

You can pass the same argument string to binmode

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.
"Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."

In reply to Re: UTF-16 on WinXP written by Perl shows whitespaces. by BrowserUk
in thread UTF-16 on WinXP written by Perl shows whitespaces. by aplonis

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