Tip: For your own safety, you should never Check for Updates in Windows 10
We all know and accept that being a Windows 10 Insider will expose you to early software with potential bugs, but it turns out besides ticking the Become an Insider box there is another way to tell Microsoft you like to live on the wild side, and that is simply clicking on the Check for Updates button.
In a blog post last week Michael Fortin, Corporate Vice President of Windows revealed that clicking that button marked you out as an advanced user willing to test early versions of Windows 10 patches.
We also release optional updates in the third and fourth weeks of the month, respectively known as “C” and “D” releases. These are validated, production-quality optional releases, primarily for commercial customers and advanced users “seeking” updates. These updates have only non-security fixes. The intent of these releases is to provide visibility into, and enable testing of, the non-security fixes that will be included in the next Update Tuesday release (we make these optional to avoid users being rebooted more than once per month). Advanced users can access the “C” and “D” releases by navigating to Settings > Update & Security > Windows Update and clicking the “Check for updates” box. The “D” release has proven popular for those “seeking” to validate the non-security content of the next “B” release.
In short with the monthly C and D patches are a proving ground for the regular and mandatory B “Patch Tuesday” releases which regular users would not normally receive unless they click Check for Updates.
And while Microsoft notes these are “validated, production-quality optional releases” we know these patches have gone wrong in the past, and have had to be pulled and re-issued. Unless you wish to be a tester it is probably wise to let the pioneers take the arrows first.
In the end, it is wise to test any software update on a small segment of users first, but many less expert users have been told Checking for Updates makes your PC safer, not riskier. Some segment of users even Check for Updates to avoid unexpected reboots when they are doing something important. How Microsoft views this group will not be transparent to them.
With the usual Christmas meetups approaching it may be wise that, instead of telling our friends and family to keep their PCs up to date, to spread the message that it is best to leave your PC alone to do its thing and hope and pray Microsoft gets it right this time.
This is from https://mspoweruser.com/tip-for-you-own-safety-you-should-never-check-for-updates-in-windows-10/