If you want to know what version of Office you have installed and check if it is 64 bits or 32 bits then here we will show you how you can learn more about the installed MS Office in your computer.
If you are running Microsoft Office 2010 then you can go to File -> Help and look for the info under About Microsoft PowerPoint.
See the value on Version 126.96.36.199.0 (64-bit)
If you are running Microsoft Office 2013 then you need to go to File -> Account.
Why should you worry about what version are you using? Some addins for powerpoint or Office will require you to specify what is the version you are running, and other software may not be compatible with the wrong version of Microsoft Office powerpoint. This is likely because when developers compile the software in .NET (C#, VB.net, etc.) they need to choose the output system for the distribution.