Internet Space 2 doesn't appear to be available anymore. I've checked various websites and all point to Network Space 2, released by Lacie and available on the official website. There is also a new Network Assistant to download for your product. I believe the Internet Space application has been upgraded and changed name to Network Space.
Use the following website to reach the downloads: http://www.lacie.com/gb/en/support/network-storage/network-space-2/
Additionally, based on what I know, sometimes the products from Lacie are not available for downloading, instead they are found on CD-ROMs delivered with the physical products.
Contact the manufacturer in case that happens: http://www.lacie.com/gb/en/company/contact/