If you only see only 32bit in windows, it means that the processor is working at 32 bit. If the processor is a 64bit capable processor, it will work at 32bit by default. You need to change the settings in bios to 64bit then only you will be able to use the 64bit ability of the processor. Please check with your motherboard manufacturer for he settinggs to change in bios to enable the 64bit feature.
Hope this is helpful to you.
What problem did you see when you tried to load the 64bit version of Vista?
What motherboard do you have (or computer)?
Windows is telling you that Windows is the 32-bit version. You need to buy/upgrade Windows to the 64-bit version.
You may be able to get that for free depending on which version you have (i.e. XP vs. Vista vs. 7) and how you got it (i.e. from school vs at a retail store vs pre-installed on PC).