Ghost user preventing uninstall of programs

Recently bought this computer second-hand, happy with it otherwise but there's something peculiar going on with the user accounts.

- When uninstalling programs I get a warning that "there are other users logged in" so the program won't uninstall correctly.
- My account (administrator) is the only one available to log into on startup.
- No other accounts show up in Control Panel / manage user accounts
- Task Manager / Users shows my user AND 'guest01' logged in and running programs though I didn't log in to guest01
- C: / Users has three folders: Public, my user, and guest01.
- Ctrl+Alt+Del / Switch User shows a blank screen for a few seconds, then brings me back to login (where my account is the only one available)

I'd like to know a) how to remove this user, and b) why it happened - the guy I bought the computer from didn't seem tech-savvy so I assume he made a mistake while trying to delete a user, but I'd like to know.

Windows 10 version 1903, Dell Inspiron 3000. Computer has been turned on and off several times since purchase. Let me know if there's any other info you need. Thanks!

Post a screenshot of what you see after you hit Win+R/cmd/wmic UserAccount get Name /enter (which should list all accounts). Like this -

I'm unable to post screenshots right now but what it says is,
Name
Administrator
DefaultAccount
Erin
Guest
WDAGUtilityAccount

- - - Updated - - -

In case it's required for some reason here it is as a screenshot:




Note the User Directory is 'Py' because that was the original name of the user. I changed it to Erin AFTER I noticed the other trouble with the guest01 account, it shouldn't be related.

MUCH more helpful to see the screenshot. When you changed User to 'Erin', you should have followed below tutorial to get rid of 'Py'. That is why it still shows up, probably as the Admin (in your command prompt, you see it following C:\Users\ instead of the desired Erin). Try the steps in the tutorial to get rid of the Py acct and make Erin the Admin. You should be good to go after that. Just make sure there are no files in the Py acct that you need to keep. If so, copy/move them to the corresponding Erin folder; eg- Music to Music, Documents to Documents, etc because all files in the Py acct will be lost in the process. Good Luck.
Change Name of User Profile Folder in Windows 10

Thanks for your reply, I'll be following that advice. However I still need help getting rid of guest01 so I can remove unneeded programs, any advice? :)

Simply logout the other user How to Sign Other Users Out of Windows 10