Tratto da un forum della esri, mai provato perche' odio win vista.

Just install Arc as you usually would and have the licence sitting in the path... c:\program files\esri\license\arcgis9x

Step 1. Install ARCGIS as you normally would and ensure the license in sitting in the path "C:\program files\esri\license\arcgis9x"

Step 2
Install ArcGis as you normally would.

Step 3 Create a File called "Start License Manager.cmd" with Notepad.

Step 4
in the "Start License Manager.cmd" file paste this code into it..
@echo off
cmdow @ /hid
cd "c:\program files\esri\license\arcgis9x"
lmgrd -z -c license.lic

Ensure you save the file as "Start License Manager.cmd"


Step 5
Run the "Start License Manager.cmd" file before you start Arcmap, Arccatalog etc. ..this will start the licence manager services needed first to allow you to run ARC map etc...