Try checking if the rename passed, and display an error message if it failed:

rename("$oldpath", "$newpath") or die "Error: $!";
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Typically, the old file does not exist, or the new file can not be created because permissions are not set properly.

Update: and try to chomp your $record.

use strict;
use warnings;

open my $fh, '<', "c:\\temp\\work.txt" or die "can not open file: $!";
while (my $record = <$fh>) {
   chomp $record;
   my $oldpath = "c:\\olddir\\$record";
   my $newpath = "c:\\newdir\\$record";
   rename $oldpath => $newpath or die "Error: $!";
}
close $fh;
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