VIsta

I recently saw that my nearest Costco that all of their computers/laptops are selling with 64-bit operating system. I see no other electronic stores that only sell 64-bit operating system computers/laptops. The only thing I am skeptical is that when you use a 32-bit operating system, you will forget it is a 32-bit operating system and programs that use 64-bit CPU will not work. It may be better or [...]

There are many reasons why not switch to Vista.

Compatibility issues programs
Uses lots of ram
needs a DVD-ROM
and even more

There are ways to get vista style without upgrading. Like vista-inspirat 2 from http://www.vista-inspirat.net/. Just look around Google for programs.