The new Microsoft kb3081424 download has just started to roll out, and is not the SR1 (Service Release 1) that was hinted in the first place. People have already started to report problems of it not installing correctly.
This is the cumulative update for windows 10, and this one is the first update since the new operating system went live. The new build number KB3081424 apparently comes with new functionality enhancements and a non-security related feature.
It seems they wanted to change the name of the build as well as the release date, which was apparently going to be released August 10. But since this new download went live people have reported it gets stuck in a reboot loop when trying to install – Is KB3081424 not installing for you?
It just comes in at 325MB in size, but this seems big enough only for a bug fix, as well as a performance update. You can get the update via Windows Update and will download using the automatic update feature.
Once the install has completed you will need to restart you computer and then away your go for the new update to work.