Office 2010 can be run for 30 days for free before needing to be active, or you will start seeing activation notification dialog. If you want to exceed the 30 days free trial during evaluation, you will need to rearm your Office 2010.
To rearm Office 2010, type in the following from an elevated command prompt:
“C:Program FilesCommon FilesMicrosoft sharedOfficeSoftwareProtectionPlatformOSPPREARM.EXE”
If it’s 32-bit edition of Office 2010 on a 64-bit operating system, run following instead:
“C:Program Files (x86)Common Filesmicrosoft sharedOfficeSoftwareProtectionPlatformOSPPREARM.EXE”
You should see a message Microsoft Office Rearm Successful if rearm succeeds. This will reset the activation Office 2010 expiration and make it good for another 30 days. You can do this up to 5 times which means you can get 180 days free trial in total.
Note: You might need to close all opened Office 2010 applications before running the rearm command.
You can download a 60 days trial version of Microsoft Office Professional Plus 2010 at http://technet.microsoft.com/en-us/evalcenter/ee390818.aspx