There are two TCP/IP ports required by Software Installer (SWI) for correct functioning of the application. SWI uses TCP/IP port 80 and port 443. These ports need to be available for SWI to work correctly. Some firewall applications may block those ports.
Any ThinkCentre or ThinkPad system running Microsoft Windows 2000 or XP using Software Installer may be affected by this symptom.
Configure your firewall software to keep ports 80 and 443 open.