Newbie Alert... Which version can i use?

I am looking at installing nopcommerce on a hosted server.
The site i use is liquidsix and it says the server my site is hosted on runs .NET 4.0 on windows server 2003 IIS6

Which version will run ok on this setup?

Cheers

Jamie

2.65

Thanks that what I thought.

I uploaded the no source version to the wwwroot of the site so its the main app. Ran the site and it came up with an 'Authentication Required' login box. See temp site for example :- http://copperfieldfarm.co.uk.uksite4.yourwebservers.com
I'm guessing this is to do with the host settings?