Not necessarily. Go into your control panel and click on system. Under "System" your computer's information is there, make, model, processor speed, and OS system type. It will tell you if you have Vista 32 or 64 bit.
My 64-bit saw it the first few times I plugged it in, but 12 hours later it stopped working. I was using the CD drivers. Edit: And the computer still doesn't see it with the website drivers. Broken POS.