Steam used to have a huge amount of servers (some from Limelight CDN) located around the world and older versions of the software used an inefficient method to connect users to the servers.
This validation, I concluded, was just a sanity check to be sure that the unexpected killing of Steam didn't corrupt any of its files.
The simplest and absolute guarantee to prevent steam from updating at startup on windows 10 is to: 1: Right Click Toolbar 2: Select Task Manager 3: Open Tab Startup 4: Change Status of Steam Client Bootstrapper to Disabled 5: Reboot Computer to test it out I'd been having that issue for a long while now and recently Steam got stuck in an endless loop of claiming to update itself only to prompt again at it's next launch. With Steam open, click the Steam menu, and choose Settings.
This issue can be exacerbated by anti-virus/internet security applications blocking Steam from doing what it wants to and reading all of Steam's files as the Steam application attempts to verify them.
Try adding exceptions in these applications for your Steam folder and restart Steam to see if this resolves your issue.
If you're certain this is not an issue with your anti-virus/internet security application and you haven't opted in to the beta, you can try one of the following to see if it resolves your problem: This will essentially reinstall Steam without requiring you to redownload all of your games or losing any of your locally stored settings.
If you're still having problems after trying all of the above, there are really only two options; A lot of falsehoods and general misinformation in this thread...
It is important that Steam is able to update and run without problems or else you won’t be able to download or play the games that you’ve purchased.
If you are experiencing problems in updating the Steam software, here we have some workarounds to fix the problem.
Since Steam randomly connects to a host, it is possible that it doesn’t cycle through all four CDN hosts.
Unfortunately there is no way to force connect to a particular CDN because there is no command line option to do that and Windows HOSTS file can only support mapping an IP to a hostname, but not mapping a hostname to another hostname.
This window absolutely CAN be permanately disabled while starting up Steam, period, end of story.