Microsoft Office 2010 trial software can be downloaded from here. If you have already downloaded and you to want check the number of remaining days left in your trial period then you can use Help menu to find out this detail.
Click the File menu –> Select Help from the menu list.
Navigate to Trial Product section available on the right hand side. This would display the details about when the trial period will expire as shown below.
You can purchase Microsoft Office 2010 from here.