This question was originally submitted in the public MS forum. I was advised to repost here.

I have a Win 8.1 box acting as a local server for an accounting system on a 4 person network. There is one Win 8.1 box connecting to it and 2 XP boxes.  User accounts matching the XP box user credentials have been set up on the Win 8.1 box acting as server. Everything was working fine until a few days ago.

Suddenly the XP box users are being asked to submit credentials in order to connect to the Win 8.1 box and these are not being accepted. The symptoms are the same as would have  been expected if their accounts had not been set up on the Win 8.1 box.

But the credentials are there and they are correct. The Win 8.1 user can connect to the Win 8.1 (de facto) server using either set of credentials used by the XP users.

I tried logging out and logging back into the XP boxes to check that the users had logged in correctly, but this made matters worse. Now when I tried to connect to the Win 8.1 (de facto) server, the user name was greyed out and set as "guest" and I was being asked for a password. No password has been set on the guest account on the Win 8.1 (de facto) server, although is has been activated. But I could not connect using a null password.

I'd appreciate any suggestions.

Hi JHipp,

The main issue is that it is not available to logon the Windows 8.1 machine normally, right?
Can we switch the user of the Windows 8.1 machine?

If it is possible, please post a screenshot here to understand the issue more clearly.

According to your description, it seems that there is something wrong with the Windows 8.1 machine`s account.
Considering this occurred recently, we could try to boot into the Windows Recovery mode to have a fix.
To boot into Windows Recovery mode, restart the machine and keep pressing "Shift",choose"Troubleshoot", "Advanced","System Restore" ,recover the machine to a previous normal point.

Considering this issue is a little weired, please perform a full scan in safe mode with antivirus software after we recovered the machine.

For the Windows XP issue:

How did you configure the the XP machine? Are you working with the built-in hyper-v feature?

The support for Windows XP has ended in April 8, 2014.

Best r