Daylight Savings in Sydney and Melbourne end on the 7th March 2013. In the lead up to this, it pays to check your critical computers to ensure they will seamlessly change their clocks to the new timezone. I suggest doing this as daylight savings adjustments have taken place at different points in the year in the past, and not all versions of Windows ship with the correct timezone info (e.g. there is a hotfix for Windows XP).
Microsoft has released a utility, called “TzEdit” which facilitates the easy manipulation of daylight savings parameters. This utility is compatible with most recent version of Windows (Windows 2000 and up), and can be downloaded from Microsoft.
Using it is as simple as running the EXE and changing the settings to match your timezone if required. In most cases the settings are correct, but it pays to double check!