I can sign in on one profile but not on another. This just started today on a profile that has been in use for more than a year. No new software added. Eset Smart Security is up to date. Eset Antivirus scan found no threats.
First, I would go to "Safe Mode" - > when you boot up the computer click "F8" and choose "safe mode" - see if you can access the profile.
Second, you can write the command: "msconfig" and choose "Startup" tab and remove software that can cause that.
if that doesn't work, go to "msconfig" and choose "Services". on the bottom check "hide all microsoft services" and uncheck services that can might casue that issue.
I would also install the free version of "malwarebytes anti-malware" and scan for spywares.