How can I legally start my own software retail business?

I buy Microsoft software wholesale from Europe and was wondering how I can legally open my own website and start selling all Microsoft Software (Windows xp, vista, 7, office etc.) Is there any licensing or anything that I need to obtain through Microsoft? Any input is appreciated. Thanks!How can I legally start my own software retail business?I'd be willing to bet that you purchasing of MS from Europe wholesale for sale in the US isn't legal.