Suddenly cannot connect to an XP machine (others work)

[simonmason]

I have a small home network setup with a handful of Windows XP machines. I recently upgraded one machine to Windows 7 and everything was configured and working. This morning the Windows 7 machine will not connect to one of the XP machines. I set up the Windows 7 machine with two logins (my wife and I) and I have the same accounts and passwords stored on the XP machine. This was working fine. The XP machines are setup in a group and the Windows 7 machine has a homegroup by the same name (not that this matters as I think this is a Windows 7 only thing). I have the userids and passwords stored in credential manager. I entered them as group\username and then password. I can ping back and forth between the machines so I know they see each other.

No matter what I do I cannot get this 7 machine to connect to the XP machine. It could have been any number of software updates or something that could have caused this problem. Recent changes that I can think of are adding Windows Antivirus. Does anyone have any suggestions for diagnosing this issue? Thanks.

 

[simonmason]

SOLVED

I just noticed that the date on the Windows 7 PC was correct but the time was not. It was showing a time about 8 hours in the future! I checked the time settings and it was set to auto update from windows time server. I changed it to a government time server - the time updated - and lo and behold I was able to connect to the other XP machine without any problems. We had a electrical storm last night and probably some brown outs (although this machine is plugged into a UPS) - don't know if this did it. Anyway, hopefully this will help someone in the future.

 

[chev65]

The time/date problem can cause sharing and password problems with Homegroups as well. Thanks for reporting back in simonmason.

Windows 7 Homegroup Invalid Passwords Because of Date and Time Settings - Resolve the issue with a simple workaround - Softpedia