You're looping more than you mean to. I think you want to pare your code down to just: 
my $flag = 0;
local ($^I, @ARGV) = (".bak", "/var/ww/htdocs/cgi-bin/user.txt");
while (<>) {
  $flag = 1 if !$flag and s/\|No$/|Yes/;
  print;
}

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Jeff japhy Pinyan, P.L., P.M., P.O.D, X.S.: Perl, regex, and perl hacker
How can we ever be the sold short or the cheated, we who for every service have long ago been overpaid? ~~ Meister Eckhart

In reply to Re: Problem changing only first occurence of pattern in file by japhy
in thread Problem changing only first occurence of pattern in file by JimJx

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