Can the Core 2 Duo's run Vista?
Vista requires a strong CPU.
These are currently the strongest CPUs one can buy.
So what do you think!? YES they run Vista, LoL (my E6400 gets a Vista performance rating of '5.1' whatever that means).
I also run Vista on a new Athlon64 3800+ (single-core) @2.4GHz, it runs well.
Vista likes lots of memory and harddisk, and powerful video.
If you have that, any modern CPU for AM2 or 775 will get you running okay.
Regards