I get "An error occurred while Windows was synchronizing with [name of time server]." when trying to automatically synchronise PC time

You can add a new rule to SPF following the steps delineated here. The application is w32Time located under System32 is memory serves right.

However if SPF doesn't complain, the problem is certainly elsewhere. I see to remember having had problems with time sync before. I really can't remember what the reason was in end. But two things seem to nag me:

• The service was stopped or in Manual or something, and needed to be in Automatic(?).
• My router was blocking it

Errors coming from the time servers alone seem unlikely. As you say you have tried others. But in any case KB262680 contains huge lists of time servers you can use.

Meanhile KB314054 reveals manual configuration instructions of the service in the registry along with a detailed explanation of all keys further down the page. Could be a case of a bad registry configuration.

All the best.

Try to run the following commands in CMD (as administrator):

net stop w32time
w32tm /unregister
w32tm /register
net start w32time
w32tm /config /manualpeerlist:pool.ntp.org /syncfromflags:manual /update

It should update the clock and print out this:

C:\Documents and Settings\user>net stop w32time

The Windows Time service is stopping. The Windows Time service was stopped successfully.

C:\Documents and Settings\user>w32tm /unregister

W32Time successfully registered.

C:\Documents and Settings\user>w32tm /register

W32Time successfully registered.

C:\Documents and Settings\user>net start w32time

The Windows Time service is starting. The Windows Time service was started successfully.

C:\Documents and Settings\user>w32tm /config /manualpeerlist:pool.ntp.org /update

The command completed successfully.