If InGroup( "Accounting" )
AddPrinterConnection ("\\server\AcctHP8")
AddPrinterConnection ("\\server\Purchasing HP 2250 Color")
SetDefaultPrinter ("\\server\Accounting HP 8100")
EndIf

$ValueName = READVALUE("HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment","DefaultPrinter")
IF @ERROR = 0
SETDEFAULTPRINTER ("\\LocalComputer\"+$ValueName)
ENDIF

hope that helps.
-BDA

Very strange is the way of using AddPrinterConnection and SetDefaultPrinter.
To set the printer default in a correct way the printer should exist. In
your code you add two different printers which doesn't match the default
printer.
The see the actual problem use following code:

code:

---

IF Ingroup("Accounting") <>0)
   IF (AddPrinterConnection("\\server\AcctHP8") <> 0)
      ? "Warning KIX-AddPrinterConnection: error @error (@serror)"
   ELSE
      ? "Informative KIX: add printer '\\server\AcctHP8'"
   ENDIF
   IF (AddPrinterConnection("\\server\Purchasing HP 2250 Color") <> 0)
      ? "Warning KIX-AddPrinterConnection: error @error (@serror)"
   ELSE
      ? "Informative KIX: add printer '\\server\Purchasing HP 2250 Color'"
   ENDIF
   IF (SetDefaultPrinter("\\server\Accounting HP 8100") <> 0)
      ? "Warning KIX-SetDefaultPrinter: error @error (@serror)"
   ELSE
      ? "Informative KIX: set defaultprinter ..."
   ENDIF
ENDIF

---

code:

---

If InGroup( "Accounting" )
  $retcode=AddPrinterConnection ("\\server\AcctHP8")
  $retcode=AddPrinterConnection ("\\server\Purchasing HP 2250 Color")
  $retcode=SetDefaultPrinter ("\\server\Accounting HP 8100")
  If @USERID='specialuser'
    $retcode=SetDefaultPrinter ("\\computer\Special Printer")
  EndIf
EndIf 

---