Windows XP Not Updating Time Correctly

So it changes back to an hour earlier than you want? If it's exactly an hour then chances are its related to Daylight Savings Time.
Have you checked DST? There are Windows patches you need for certain servers to correct DST.

Is the server completely patched up etc?

Open a command prompt and type
w32tm /resync

This will resync the PC with a local domain controller. If the time is still wrong, then your DC has the incorrect time

The resync would be whats causing the time to change back every 10 minutes.

are you blocking access to NTP servers with a firewall?

if it a domain member it will synchronise time with the domain controller

Ledaouk, thats what I thought but all the other computers are fine. Where would I look on the server to be sure its actually syncing with that computer for time?

Remixedcat, all other computers are fine so no its not a firewall issue.

Scottyworld/andoss - we have done a w32tm /resync and it sets back an hour when we do so so yes andoss is correct.

andoss (first comment) - It has SP3 and claims it is up to date. Whenever we check or uncheck DST it still goes back later.

Again, all other computers are fine.

your OSes built in firewall might not be allowing it. or any other security software. Also make sure bios is also reporting the right time as well.

Go to HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Services \ W32Time \ TimeProviders \ NTPClient \  and check if there is time server,
also check if you installed an application that syncronize with internet timing.

please try what I've presented in the screenshot.

please select from another server on the list.

Its on an XP machine and I don't think it has that screen, where do you click after you are at Date and Time. Also, I had discussed the bios above, please read everything posted and please provide a process for getting to the screen shots or ideas you give me. (guides get better ratings..)

right click on the task bar>adjust date/time>"internet time" tab>"change settings" button>use drop down menu to select desired server>ok>ok>done!

What OS do you have? the computer is on XP and doesn't have the internet time setting and the computer I am on now is 7 and doesn't have that setting. I would assume our server controls the time and therefore doesn't have that option.

LeDaouk: Can you offer me an  opinion on where I can find the time synchronizing option on the server?

windows server 2008 x64. did they remove the option from windows 7??? why would they?

I have no idea, I can check when I go home. I am not saying they removed it, I was trying to say that maybe the domain controls it and therefore its not shown.

that could be a possibility. sorry this is so frustrating for you.

The internet time tab does not appear on an XP machine when it is connected to an AD domain, hence why you can't see it.

Have you tried removing the PC from the domain and rejoining it again?

Have searched our WSUS (Windows update) server for updates that may relate to this and have found one that applies to a time zone update. It may be worth checking you have it installed already, or install it and see if it fixes the issue.
http://support.microsoft.com/kb/2443685

Worked fine, thanks!