You are correct. Currently available Visual Studio versions (VS 2013 and VS 2015) require Windows 7 SP1 or newer.
By far the best solution, IMO, is to upgrade your OS. But if you look around, you might be able to find older VS versions that will work with Vista.
For example:
There is one possible workaround for you here:
http://download.microsoft.com/download/8/B/5/8B5804AD-4990-40D0-A6AA-CE894CBBB3DC/VS2008ExpressENUX1397868.iso
This is the all in one ISO download for VS 2008 Express, which does not require a registration key.
