Many of my friends ask me whether to upgrade to vista or not. Many of them use windows Xp currently and they were very eager to try Vista. Vista is really good like Xp, and it is very good in graphics similar to Macosx. However you have to face a higher hardware requirement for using vista. You must at least have 512 MB of RAM (Random access memory).If you do not have the requirements as for windows vista your computer will be slow. Windows vista is really great but you must have the required hardware. If you are going to buy a new PC, then you can buy the required hardware and have windows vista.
If your computer is running using a processor lower than Pentium 3, then do not even think of putting vista in your computer.