Synchronizing Time in Windows XP

Can anyone help or shine some light on this subject with synchronizing time in windows XP? I have four computers and they all will display error message when clicking on "Update now".
"An error occurred while Windows was synchronizing with time.nist.gov".

I Goggled the error message and found many discussions about this issue (which went way back sometimes to 2004), but no solutions. I checked Dell forum.
This problem has developed for me just recently (likely around DST change in early March) as I used this feature as far as I can remember and it always worked flawlessly. I am behind router but, have not changed any firmware or settings in the router for at least one year.
All four computes have different firewalls. I disabled firewalls. I enabled and disabled Windows XP firewalls. I changed time servers to time.windows.com (on one computer, I have six different servers listed). Enable disable DST. Turned automatically synchronize with an internet time server on and off. Ran w32tm /unregister  w32tm /register.
I know there is a third party software that I could install however, I would like to make the one in Windows work as I never had a problem like this in the past.

This link tels me I am not alone

http://www.serverforumz.com/Time-longer-automatically-updates-ftopict91823.html

Thanks, Ratz

 

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