The Anniversary Edition update is a pretty big deal. In many ways it is similar to a full OS install and is more of an upgrade than an update, so....
The first thing I would recommend is to make sure all your critical data is backed up and secure on an external resource, and also to make a disk image of your current install as discussed here
https://www.windows10forums.com/threads/please-for-your-own-peace-of-mind.794/
So you have a strong fall back position should things not go exactly as planned.
Then.... because in some cases, certain peripheral devices might cause some problems with your upgrade, you may want to make an effort to reduce your computer to its' basic components by disconnecting any and all USB connected devices.
I would then attempt a clean boot of the system as explained here
https://support.microsoft.com/en-us/kb/929135
Easily done, easily undone.
Basically you're just disabling all the Startup Items and All
non-Microsoft services.
Be sure to check the box to hide Microsoft Services, as you don't want to accidentally disable any of those.