Error while Windows was synchronizing with time.windows.com

You need to reset the windows time (NTP) settings back to defaults, here's how:

Open a command prompt (Start-->Run, type CMD.EXE, click OK)

Run the following commands to reset the windows time service to defaults:

net stop w32time
w32tm /unregister
w32tm /register
net time /setsntp:time.nist.gov
net start w32time

Here are a list of NIST time servers if you'd rather use a different one:
http://tf.nist.gov/service/time-servers.html

@chakote,

I got error:
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C:\>net stop w32time
The Windows Time service is stopping.
The Windows Time service was stopped successfully.


C:\>w32tm /unregister
The following error occurred: Access is denied. (0x80070005)

C:\>w32tm /register
W32Time successfully registered.

C:\>net time /setsntp:time.nist.gov
The command completed successfully.


C:\>net start w32time
The Windows Time service is starting.
The Windows Time service was started successfully.


C:\>
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My account is a member of Admin group.

And I'm still can't sync my Internet Time using time.windows.com or time.nist.gov.
But the error not like it was before:

"An error occured while Windows was synchronizing with time.nist.gov/time.windows.com."

The registry settings are not cleaned up if the unregister fails.  
Try creating a new account that is a member of the "Administrators" group and running the w32tm /unregister and w32tm /register commands (and those that follow) again.

I have the same issue.  When I try to unregister the w32tm I also get the same error message as noted above.

I have tried to make another admin user account.  
I then logged out all other users.
Logged in with the new admin user
Then ran the above suggested solution, and it still generated the same error when trying to stop the service.

I found on Microsoft forum: http://www.microsoft.com/windowsxp/expertzone/newsgroups/reader.mspx?dg=microsoft.public.windowsxp.general&mid=b51668c7-7d9a-4a8d-bd9f-3a72cfc953f4

that we must type the "w32tm /unregister" twice. But, still no luck :(

Looks like we must another server to get it work properly...

Yes, did the w32tm /unregister twice anyway...well if at first you don't succeed punch buttons repeatedly philosophy :)

Also tried using different time servers, but still no luck.  Its not a major issue for me, but I just happened to find you with the same issue.  Thought I would drop in with the same problem to see if my problems in some way can help people find a good solution for you.

But it work before. I dunno why it refused now.

Check the permissions of the following registry key:

HKLM\System\CurrentControlSet\Services\w32time

Make sure that administrators have full control of the key and all subkeys.

Checked and yes, Administrator and SYSTEM  have Full Control and Read in the Allow column.
Who is the group of CREATOR OWNER? This user have Special Permission (allowed).

I clicked Advanced button, point to Owner tab. I changed the owner from Administrator to my username (member of Administrator too). Still no luck...

Creator owner is a builtin system object.. It represents the user who created or is the current owner of the specified resource

No objections, the reuqestor has been added to my personal block list.

Not just XP, Vista also. Just once I can sync with time.windows.com on Vista. Right now, I just finished reinstall my Vista and still can't sync...

I can sync my Vista with time.windows.com now!

I use TuneUp Utilities which will automatically added several server:

time-nw.nist.gov
time-a.nist.gov
time-b.nist.gov

Because of I'm still can't sync my Windows with time.windows.com for the first time, then I try the added server one by one. My Windows can sync with them.

Last, I try with time.windows.com and it work.

But looks like I must use the additional server first before my Windows can sync with time.windows.com.

Just trying to sync again (Vista) and failed with time.windows.com server. The 2nd server, time.nist.gov, sucessfully. Back to time.windows.com server again and sucessfully too.

I thin we must make a provocation to time.windows.com server by using another server that works and the sync with time.windows.com server.

O.K., nothing has worked, yet.

    When I use w32tm /unregister, it always returns
w32Time successfully registered.
     It has never returned unregistered. I have repeated the command many times.