As of a week ago, I've been getting the "Sorry, we couldn't update Oculus. Restart your computer to try again later" error message anytime I start up Oculus Rift. I've tried restarting both my computer and the Oculus software, but to no avail.
Suggest you download the latest Oculus setup and reinstall. Make sure you run it as admin and also temporarily disable anti-virus software and firewall.