The company offers a free version of this ost2pst.exe software for your evaluation. To evaluate the software with no obligation you can click on the download link. This will allow you to test the features and functionalities of the software to your satisfaction.
However, you need to ensure the basic system requirement for the software:
Disk Space Requirements:
10 MB free space
Supported OS: Windows 8.1/ Windows 8/ Windows 7/Windows Vista / 2003 / 2000 / XP (with Service Pack 2 and 3)