I've Windows Vista 32 bit, Can I play modern games (Bioshock Infinite, L4D2, Saints Row IV) without a problem?
Read the system requirements for the games. With Vista, probably the biggest issue would be how good your hardware is, not the OS.
This is very true, and an excellent observation. The OS being used will likely not be your limiting factor. Look closely at the hardware requirements of your intended games against the hardware you actually have.