A Guide to Time Synchronisation with Windows Vista

All computers have clocks of course although the real time chips (RTC) that inhabit most PC’s are not the most accurate of timepieces and are prone to drift.

This may not matter much to the average home user although when it comes to time sensitive applications this inaccuracy can be at best annoying (an email arriving before its been sent) or at worst leaving your machine open to security threats.

A universal time (UTC) does exist and allows the global industry to communicate and trade even across time zones. UTC was developed to ensure that everybody used the same time reference, preventing problems with time sensitive transactions such as on the stock exchange.

Windows Vista has an inbuilt time synchronisation facility already installed called Windows Time and it is pretty easy to setup and to synchronise a machine with UTC over the Internet. This will ensure that the clock on your computer is accurate to UTC time and is constantly updated to ensure the time does not drift.

To synchronise your Windows Vista machine to an Internet UTC source simply follow these instructions:

1. Right click the clock in the system tray.

2. Click adjust time and date.

3. Click the Internet time tab.

4. Click change settings.

5. If you are prompted for a password or for confirmation, type the password, or click Continue.

6. Select the server you want to use (such as windows.time)

 7. Click the Update now button.

 8. Click Ok twice.

If problems occur then another method of synchronising your computer is possible via the command prompt by running w32tm / resync. This should activate the windows time service.

Note: Microsoft and other operating system manufacturers recommend that an external hardware source should be used to synchronise a computers clock as Internet time servers can not be authenticated leaving systems vulnerable to security threats.

There are specialist time servers that connect to a UTC source using either the GPS network or a specialist radio transmission. These servers use NTP (Network Time Protocol) to synchronise machines on a network to one UTC source and are easily installed and relatively inexpensive.

Window Vista also has a facility to add extra clocks to the system tray. This allows different times from different time zones to be displayed on the computer. If the clock has been synchronised with a UTC source then all these clock will present UTC time converted to whatever time zone is required.

To add additional clocks simply follow these instructions:

Choose change date and time settings.

1. Left click the clock and click Additional Clocks tab.

4. Put a check mark in Show this Clock.

5. Select the time zone.

6. Enter a name for your new clock.

7. Click apply, then when you click on the Clock icon you’ll see your new clocks.