First thing is,i have Windows vista Ultimate and 1Gb Ram.i want to install xp on it.but i saw lots of version of xp available.so can someone list all the xp version and tell me what is the best xp at this moment.the only thing i know is it should be xp profesional.other than that no...(i saw there is gold edition,royal edition and many more) and they are downloadable.plus it says its a genune one,if you want the link tell me. right now i have a copy of windows xp profesional SP3 with Vista Theme.i'm afraid its not genuine.how to know if the software is genuine?? can i use microsoft office 07 and other latest apps that worked on my vista on xp?? Thats all for now.i'll come back later with more questions.thanx for reading. **the bold words is the one that i really need answers.