64-bit option at startup

I want to buy a computer with 64-bit Windows 7 Pro. Most of the options I'm seeing are for 32-bit. I was told that I can purchase 32-bit and choose 64-bit at startup. Is this correct? How does this work?

Some computers offer that choice, but it's best to just get one that has the x64 OS already installed on it.

Ask the salesperson where you plan to buy, if in person. If not order it online with the Windows 7 64-bit installed.

32 bit computing is going by the wayside, has been for a couple of years. Choose the 64-bit and you'll be fine and have the most modern computer OS there is.