As most people know, when receiving a document in Microsoft's proprietary format such as docx and xlsx, you need the original MS Office suite to open these documents.
Forget about the other clones or open source software and office suites, they all use the same cracked format versions which are not 100% compatible with the original Microsoft formats.
Well, I don't know about you, but I am not willing to pay $100-$500 just to open a document. So... the easiest way is to download Microsoft's FREE document viewers. As surprising as this is, they are indeed very much free to be downloaded.
Here you can download them all - Word, Excel, and PowerPoint Viewers:
The other problem most people have is when installing a software application and it reassigns a document format to itself, like rtf or the doc format that is being used by your favourite app already in use.
To fix this, there is a simple procedure to follow, just right-click on the document you want to change and select the "Open With" option. The popup menu will then list all the applications capable of opening your document, just select your application of choice and that is it, fixed.
If your favourite application is not listed, select the "Choose Program..." option on the bottom of the menu selection. Out of the very extensive list, you will be able to get your application selected.
So to open any and all software application documents, whether supported or unsupported, the above information will get you reading all your important documents in no time.