I got bored so fumbled my way thru mirc scripting.
Now this is my first EVER attempt at mirc script so point out where I have gone wrong and could improve please(but dont be to hard on me I want to learn)!
Basically put all the below as a remote.
To note I ripped 3 random scripts off pretty bad and I forget who they all were, uh sorry to them for lacking credit.
This script will fix the behaviour of Mirc on Vista for opening links (double click a link to open it in the system DEFAULT browser.)

Code:
alias RegRead {
  if ($1 != $null) {
    var %a = regread
    .comopen %a WScript.Shell
    if !$comerr {
      var %b = $com(%a,RegRead,3,bstr,$1-)
      var %c = $com(%a).result
      .comclose %a
      if (%c != $null) return %c
      else {
        return error! when reading or key does not exist
      }
    }
  }
  else { return error! complete data }
}

alias replacew {
  var %a = $1, %g = $iif(3 // $calc($0 - 1),3,2), %i = 2, %re, %v1
  while ($eval($+($,%i),2) != $null) {
    %v1 = $v1
    %n = $eval($ $+ $calc(%i + 2),2)
    if (3 // $calc($0 - 1)) %re = /((?:\Q $+ $replacex(%v1,&,\E\S+\Q,*,\E\S*?\Q,?,\E\S\Q,\E,\E\\E\Q) $+ \E ){ $+ $calc($eval($ $+ $calc(%i + 2),2) - 1) $+ })\Q $+ $replacex(%v1,&,\E\S+\Q,*,\E\S*?\Q,?,\E\S\Q,\E,\E\\E\Q) $+ \E/i
    else %re = $+(/\Q,$replacex(%v1,&,\E\S+\Q,*,\E.*\Q,?,\E.\Q,\E,\E\\E\Q),\E/gi)
    .echo -q $regsub(%a,%re,\1 $+ $replace($eval($+($,$calc(%i + 1)),2),\,\\,$,\$),%a)
    inc %i %g
  }
  return %a
}

on *:hotlink:*//*.*:*: http $1
on *:hotlink:*www.*:*: http $1
alias http {
  var %ProgID = $RegRead(HKCU\Software\Microsoft\Windows\Shell\Associations\UrlAssociations\http\UserChoice\ProgID)
  var %Browser = $RegRead( HKCR\ $+ %ProgID $+ \shell\open\command\ )
  var %Launch = $replacew(%Browser, .exe*, .exe" " $+ $1")
  run %Launch
}

Oh and I had Windows version check working but assumed noone would run the script but those on Vista wink