I have been using M.E. for a long time with good success but have been given some software that requires X.P. So, I am considering upgrading but I have heard that one needs to be careful and not buy from unauthorised places. Also that there is problems with the original version of X.P. and there is an upgrade package but that Microsoft will no longer support the original version. I see that there is in testing Vista but who knows when that will be released. So I would like to know some places to buy and if I can upgrade to the most current X.P.

Thanks