After upgrade to 1809, Windows XP won't connect to Win10

Check this bit now and, if relevant, take action now.
1 Is this user account your admin account?
2 Is this user account your only admin account?
- If the answers are Yes then do not wait, create a new password-protected local admin account now so that you can keep control of your computer if anything in that user profile deteriorates further.
- Personally, I keep two of these additional admin accounts so I am always ready for any user profile corruption. I call them something like AdminMain & AdminBackup, they are both local accounts [to keep things as simple & reliable as possible], they both have long, random passwords to avoid making them a gift for hackers and their passwords are written down on a piece of paper in a thing attached to my keyring [see photos at para 5.2.2 of Fix UAC prompt has greyed out or missing Yes button - TenForumsTutorials].
- If you feel insufficiently motivated to do all this now, read the whole of the above tutorial to encourage yourself.

Add Local Account or Microsoft Account - TenForumsTutorials

In brief, whilst logged in to an Admin account,
- go to Settings, Accounts, Family & other users
- Add someone else to this PC & follow that through
- Select the new account that will appear in a list under that Add someone … button, Change account type
- Give admin permission to proceed, select Account type Administrator, OK

I'll respond to your other points in a separate post.

Denis

I'm a bit tied up responding to the previous post so here's a brief response to the new one just to get it out of the way.

phrab said:

Neither one of my admin accounts uses a password. I'm willing to add one, …

The one that you are currently not logged into is therefore a gift to hackers - they can log in without having to crack a password.

but prefer to logon without entering it each time. I don't want it to prevent me from copying files back & forth to my XP machine.

All this can be set up so you rarely have to put a password in anywhere but are still protected by it.

Since I have another admin account, is it as urgent to create a 3rd one?

No. I used to contribute to another forum and spent so much time helping out users who had corrupted their only admin account that I became overly cautious.
- I use the AdminMain for routine troubleshooting so I do not end up giving undue additional access permissions to the account I am routinely logged into and which is therefore the most likely to be attacked.
- Because AdminMain is in use sometimes, it is susceptible to user profile corruption so I have AdminBackup held in reserve in case that should ever happen.

Denis

User profile corruption tends to happen when you force your computer off without going through the shutdown sequence [such as when the computer freezes so that you cannot do anything but force it off].

1 Selecting Everyone in the sharing procedure does not cause user profile corruption. Did you do anything else such as try to alter access permissions on folders?

2 I don't recognise that Event viewer diagram and the Windows 10 Event viewer uses a slightly different name [Application & services logs, Microsoft-Windows-User Profile Service/Operational]. Is that diagram the WinXP Event viewer?

3 The only "fixes" I have ever seen for user profile corruption have, essentially, been procedures for creating new ones. Example - Fix You've been signed in with a temporary profile - TenForumsTutorials I have never seen a proper fix as such.

4 Some people report various fixes from time to time such as deliberately making the corrupted account a standard user account then making it an admin user account then making it a standard user account [rinse & repeat half a dozen times]. Apparently at least one user found that the corruption had disappeared afterwards.

5 I always have to muddle through learning as I go whenever I have to work with a new part of Event viewer. I would have to post a new thread specifically for those Event viewer errors if I hoped to get any advice about them.

6 Are there any fault indications when you log on?

7 Just to avoid any misunderstandings, I have no idea what your Event 1534 entries are and I have no idea whether or not they are of any concern at all. So you'd have to create a new thread asking about them.

Denis

About avoiding passwords as you use the network -

1 Create / decide upon an admin user account on every computer and make sure you use the same password as well as the same account name.
2 From each computer, connect to a shared folder on the other[s]
3 You will be challenged to enter an account name & password - use the common one & set the checkbox for remember credentials [or whatever its latest label is]
4 After you have done this once, you will never get challenged again as you access your shared folders.

Denis

About avoiding passwords as you log on to a Windows computer -

1 Set an account password on every account as mentioned in the earlier post
2 Log in to the account as normal and enter the password
3 Run the built-in utility netplwiz and select an account for automatic logging in {you will still always have to enter the password for your backup admin account but you have them all written down and attached to your keyring by then anyway}.
4 The selected account will get logged in every time you restart your computer.
5 If you log out of the selected account you will need to enter its password to log back into it or deliberately restart the computer to avoid hassle.
5 Detailed instructions are in How to Automatically Sign in to User Account at Startup - TenForumsTutorials - I suggest using the Option 1 procedure in it.

Writing down your password is essential in all cases
- If your password is any good you will forget it.
- If you use netplwiz to avoid having to keep entering your password, you will forget it.
- You might know that there is a procedure for creating a "Password reset disk" [for local accounts only] but that merely creates a file on a USB stick that you then have to keep securely. It achieves nothing more than having the password written down achieves.
- Keeping a piece of paper securely seems to me to be far easier. By the way, the Amazon link [in para 5.2.2 of Fix UAC prompt has greyed out or missing Yes button - TenForumsTutorials] for dog tag things for your keyring was not chucked in haphazardly. There are many alternatives even on Amazon so I worked through shortlisting them and the shortlist ended up having only one entry - Pet ID Barrel Tag Address Label Tube If I lost my current one that is what I would buy. I appreciate that you'll have to search around your regional Amazon site for an equivalent so I should point out that I chose it because
- - Size (Lx Bottom Dia): Approx. 28 x 9 mm - I know from experience that it can hold a piece of paper 1/2" x 11".
- - It has a screwdriver slot underneath that I can swing off to tighten it so it can live in my coat pocket while I'm away without my having to worry about it working itself loose.

Denis

About routinely using an admin account -

1 It is not recommended but I also do so [as do others].
2 There are frequent allegations about being logged in as admin allowing malware to penetrate through and adopt admin level permissions without any admin challenge being displayed [just as if you had brought up that admin challenge dialog and clicked on the Yes button yourself but hidden away from sight].
3 I guard against that risk by having UAC set to its highest level. All the hacks I have investigated are thwarted by this. This means that I also get challenged when I change some Windows settings but after the first week of installation / updating to a new version that is almost all taken care of so it hardly ever happens after that.
4 I do always read what the admin challenge says in the Show more details link it contains. Only by doing so can I be sure that I am approving what I think I am approving.

UAC [User account control] is the function that allows you to raise the account's permission level for a specific task [i.e. that controls bringing up the admin challenge].
- It has great security significance for us as users but was actually conceived of as a mere convenience [admins in the workplace can apply their elevated permissions in order to address a user's problem without having to switch out of that user account and log in themselves].
- Remember that even when you log in to an admin account, you are constrained to standard user permission levels until you approve higher levels using the admin challenge. And that approval applies only to the specific task approved.

To set UAC to its highest level through the UI -
- Windows button, Windows system, Control panel - set it to View by - Small/Large icons
- User accounts
- Change user account control settings {you'll get an admin challenge here}
- Drag the slider to the top level "Always notify" then OK {you'll get an admin challenge again here}
How to Change User Account Control (UAC) Settings - TenForumsTutorials

I keep writing admin challenge just to avoid using the correct terminology.
- If you are logged in to an admin account, the admin challenge shows Yes & No buttons. This is called the ConsentUI.

- If you are logged in to a standard account, the admin challenge shows an admin account name & a password entry box as well as Yes & No buttons. This is called the CredentialUI.

- Both the ConsentUI and the CredentialUI can also be called the ElevationUI but nobody ever does. Everybody just calls them all something like the admin challenge / admin prompt / …

Denis