So, I'm presuming when SQL Express was installed, you didn't specify the service account, in which case the installer would've created the account.  As for why you didn't see it...

My troubleshooting mantra has largely been "always check the basics, even if you're *sure* the problem's not there."  Because all to frequently, it's going to be, it's going to be something you...

Seeing as getting on  newer version of SQL doesn't sound like an option (near-term) you're going to need to look into some other method.
Possibly setting up a job that...

You know all the cracks sysadmins make about people using their Recycle Bin or Deleted Items as "archive" storage?
Yeah, I did something similar and it came back to bite...

That feeling when you find out you asked someone to put in a ticket to have a user removed from the login list, only to find out they didn't need...

Grab your popcorn for this topic!
https://www.sqlservercentral.com/Forums/2009853/The-Linux-CoC
It's trying *real hard* to descend into politics, rather than a discussion of the Editorial itself...

Steve's doing his best I...

When the certificate you're restoring was originally backed up, it was encrypted with a password.  Which, if you think about it, is only sensible, as anyone who gets the certificate...

(Please note, I've not been to SQL Summit)
I wonder how much of the harassment stems from a "what happens in Vegas (Summit) stays in Vegas (Summit)" sort of attitude,...

I would expect that yes, you can use both features simultaneously.

TDE encrypts your data files AT REST while DDM "masks" the data within the column(s) specified.
TDE does *NOT* actually...

Sad news today:
Legendary Creator Stan Lee, Who Changed Comics and Pop Culture Forever, Is Dead at 95