How2NotFail

File extensions are usually the source of a lot of problems for novice windows users. Having them hidden makes it easy for file types to get confusing and even obscure, since you only have icons to go by. In some cases, it may even lead to the unknowing opening of an infected file, that packs your system full of fluffy virus’s and malware. ( Reference: Which Downloads Have a Virus )

What are File Extensions?
File extensions are the few letters and numbers that follow the last “.” (period, or ‘dot’ as it is commonly referred to as) at the end of your file, that associate it to a particular program. That is to say, windows keeps a list of file-types, and based on your system settings, will try to open that file-type with whatever installed application it has available (and associated to that file-type). For example, if you have an image file like MyDog.jpg, windows may try to use MSPaint to open it.

Why Can’t I See Them?
Good question! Microsoft likes to disable that little feature in case you don’t know what you’re doing. Should you accidentally rename a file extension (.xyz), windows will no longer know how to open that file. It’s a fail safe. Once your system is set to show file-types, it is important that you only rename the first portion of the file name. Ex. “MyDog.jpg” becomes “MyBestFriend.jpg“. The .jpg must stay the same in order for windows to still recognize that particular file as an image.

Alright, I get it. How do I show file-types?
1. Double Click any folder, or the Computer icon on your desktop
2. Tools->Folder Options
3. Click on the View Tab
4. Uncheck “Hide extensions for known file types”
5. OK

*Note* – The instructions above are intended for Windows Vista, but should be very similar in other windows versions as well.