In seven months since owning the SP4 rarely has the fan come on...until today. This morning the anniversary update occurred and ever since the computer gets noticeably warm sitting on my lap and the fan keeps coming on. The only thing I've been doing is reading my email and looking at webpages. There is nothing running in the background. This sure is disappointing as it seems pretty clear to me that the only thing that has changed is the installation of this latest update. Do you think another update will be forthcoming that will correct this behavior? EDIT: It's been a full day since writing the above note. I am pleased to report that the "issue" seems to be gone.