When you install Windows Vista Upgrade Advisor it will perform an analysis to study the different components that form the computer and check if the Windows Vista operating system will work properly on it. Once it has finished, it will indicate if you can install Windows Vista. If not, Windows Vista Upgrade Advisor will indicate you in which aspects your computer doesn't fulfil the requirements, and what elements or features would be necessary to be able to use Windows Vista on your system.
Don't risk updating your operating system without knowing for sure if your computer meets all the requisites to do so. Use Windows Vista Upgrade Advisor and check it out.