After installing Office 2010, user will have initial 30 days of free evaluation period before having to activate the product for lifetime continuous usage. During the early technical preview build of Office 2010, a method of rearming no-activation or activation-free period of Office 2010 was discovered. With the release of final RTM version of Office 2010, the rearm command has been made simplified.

In order to rearm Office 2010, just run the OSPPREARM command located at the following folder:

%Program Files%\Common Files\microsoft shared\OfficeSoftwareProtectionPlatform\

For example, open a command prompt windows (in Windows 7 or Vista, open an elevated command prompt window), and type the following command:

C:\Program Files\Common Files\microsoft shared\OfficeSoftwareProtectionPlatform\OSPPREARM.EXE

Rearm Office 2010

Note: Change the path if necessary, such as when installing 32-bit (x86) Office 2010 on 64-bit OS, where the path may be located at %ProgramFiles(x86)%, i.e. C:\Program Files (x86).

The rearm is provided in Office 2010 as a convenient for corporate customers as Microsoft now requires all installed copy of Office 2010 to be activated, including licenses sold through volume licensing. A total of 5 rearms is possible, where after reset, additional 30 days of free usage is allowed without proper activation. When timed correctly to rearm Office 2010 at last day of current cycle’s expiration days, the 5 rearms can extend and prolong the free usage of Office 2010 to half a year long.

According to TechNet, rearm function in Office 2010 is mainly for corporate customers who deploy Office 2010 via KMS activation or MAK activation, as rearm allows grace timer to be reset to 30 days of grace, freezes the grace timer, and resets the client machine ID (CMID). If the deployment image does not been rearmed, users will see notification dialog boxes at the time that the image is deployed, instead of 25-days after deployment. The 25-day grace period allows ample time for a KMS host to be found and activation to succeed. If activation is successful, users do not see notifications to activate.