SEATTLE (Reuters) - Sales of Microsoft Corp's flagship Windows software disappointed for the third straight quarter, taking the gloss off better-than-expected earnings that were aided by an unusually low tax rate. (http://feeds.feedburner.com/~ff/reuters/topNews?d=yIl2AUoC8zA) (http://feeds.feedburner.com/~ff/reuters/topNews?i=ECp6fqnSb90:CtEAOI5IvmQ:V_sGLiPBpWU) (http://feeds.feedburner.com/~ff/reuters/topNews?i=ECp6fqnSb90:CtEAOI5IvmQ:-BTjWOF_DHI) (http://feeds.feedburner.com/~r/reuters/topNews/~4/ECp6fqnSb90)