The Windows Time (W32Time) service maintains date and time synchronization on networked computers that are running the Windows operating system. It uses the Network Time Protocol (NTP) to synchronize computer clocks so that an accurate clock value, or time stamp, can be assigned to network validation and resource access requests. The implementation of NTP and the integration of time providers make the Windows Time service reliable and scalable for administrators. For computers that are not joined to a domain, you can configure the Windows Time service to synchronize time with an external time source.

If the Windows Time service stops or if you disable it, date and time synchronization is unavailable in the network or from an external NTP server. There are two possible scenarios:

• If you stop the Windows Time service on a workstation, the workstation cannot synchronize its time with another source, but no other external server is affected.
• If you stop the Windows Time service on a domain controller, the same effect as in the previous scenario applies, but domain members are also unable to synchronize time with it. This inability to synchronize may adversely affect time synchronization in the organization.

This service is installed by default in Windows 7 and Windows Server 2008 R2, and its startup type is Manual.

When the Windows Time service is started in its default configuration, it logs on by using the Local Service account.