Quite a few of us will already have had this update and, for many, it has been without problem.
However, if not, I suggest you backup important files/programmes/bookmarks etc., before downloading and installing it.
Apart from it being large and therefore possibly taking a long time, ie several hours, to download and install it appears to have caused problems for some. A couple of members on another forum have found their machine was unusable after they tried to download and install it and they needed to do a fresh installation of Windows.
I cannot be sure the downloading of this update caused a problem here but it seems our daughter's laptop (it is around a year old and has been faultless until last Saturday) was one of the unlucky ones. After around nine hours (over a couple of days) of trying various ways to put it right the only way was to re-install Windows. Fortunately she managed to save important stuff.
Thanks for the warning Tringa. I'm very wary of MS updates these days. My PC was completely unusable after a major update a year or so ago. Had to take it to a specialist company who found that all my data was so corrupted the only solution was for them to wipe the hard drive and reinstall Windows. Lost lots of stuff in the process. To make matters worse, often we get no choice about downloding these updates - MS just takes over the computer.