Its tough to use pirated version in the system. Because due to pirated version your system will get spoiled when you are in online due to microsoft. They will easily find your pirated software and many problems will be occur due to that.
Its better you buy an original Ms-office is stores to be safe from all these kind of problems. Or otherwise use the best way of downloading the Open-Office from any of browser engines. It will be helpful for you to usse long duration in your system.
You cant get these kind of utilities in the pirated software. Product key for pirated wont be giving life of your software long. Better prefer Open-Office.