Cath,

NIS 2012 will work on VISTA 32 bit or 64 bit so that's no problem but could you check to see if that screen mentions Service Pack and if so what number is alongside it.

My VISTA unstallation is out of action but Windows 7 is not very different from what I remember so here's my Windows 7 System Information screen:

and you will see where it says Service Pack 1 which is the latest for Windows 7.

However there are additional Service Packs for VISTA ... Service Pack 1 or later is needed by NIS 2012 so if your screen does not mention Service Pack then you have the original VISTA (like Service Pack 0) and need to update which you can do here:

http://support.microsoft.com/kb/935791 

I hope that helps.