Lookup the following macros in the KiXtart manual
@ProductSuite
@ProductType

or you can even run code similar to this.

Code:
Break On
Dim $SO,$HKLMSCCS,$Server
$SO=SetOption('Explicit','On')
$SO=SetOption('NoVarsInStrings','On')
$SO=SetOption('WrapAtEOL','On')
 

$HKLMSCCS='HKLM\SYSTEM\CurrentControlSet'
$Server=ReadValue($HKLMSCCS+'\Control\ProductOptions', 'ProductType')

If $Server<>'WinNT'
  'This is a Server.  Quit or run code for server' ?
Else
  'This is a Workstation.  Quit or run code for Workstation' ?
EndIf