Voting Question: Windows 7 With 1gb and 512mb Of Ram? HELP!?

Hey,Well i need help with a decision problem..i know have 512mb of ram but i am thinking about purchasing 1gb of ram just so i can get Windows 7 that's a total of 1gig and a half,my computer can have up to 4gb's i am getting 3 soon so i will be good but im trying to think should i get this 1gb know or get a mp3 player and get the ram later...?....the reason i want the ram is because i want to upgrade to windows 7 so can i do it or what and will it run slow? i really need your help AND ALSO I DONT WANT NO ONE SAYING STUPID SHIT LIKE YOU NEED A UP GRADE OR SHIT LIKE THAT...Thanks :D