I'm trying to fix two Win 10 computers that recently downloaded an update and now they are stuck in an endless reboot. They attempt to uninstall the update, fail, and reboot, continuously. By booting to a Dell recovery USB I can get to the advanced startup options. It gives me the option of rolling back the update, but this fails. It does not give me the option to boot into Safe Mode; I tried to do it by command prompt, but it didn't recognize the command. One of the machines has an automatic restore point, but the restore failed. I tried the "net stop wuauserv" command, but it says this service name is invalid. I really don't want to just reset or reload the computers, but I don't know what else to do. Any ideas?