The blog of Windows Wally, a Windows Support Technician helping common people solve frustrating computer problems.

How To Open FN_ Files

Reader Question:
"Hi Wally, I am having problems opening FN_ Files and wondering how to fix it?"
    - Brian D., New York

 Recommendation:   Scan your Windows registry for problems affecting PC health.

  • Step 1 : Download PC Repair & Optimizer Tool (3.32 MB)
    (WinThruster for Win7, XP, Vista - Microsoft Gold Certified).
  • Step 2 : Install the software (30 seconds). After installing, an automatic scan will begin to find registry issues that could be causing PC problems.
  • Step 3 : After the scan completes (15 seconds), click "Fix Issues" to repair all registry problems.

Setting up weekly (or daily) automatic registry scans will help prevent system problems and keep your PC running fast and trouble-free.

Wally's Answer:

What Are FN_ Files?

FN_ files are Uncommon Files primarily associated with CAD File.

(Other files may also be using the FN_ file extension. If you know of any other software using the FN_ file extension, please contact us so that we can update our information accordingly.)

Opening FN_ Files

The easiest way to open a FN_ file is by double clicking on it, which will let the computer decide the best way to open it according to the Windows FN_ file association settings.

If your computer opens your FN_ file, but it's the incorrect application, you'll need to change your Windows registry file association settings. In other words, Windows is associating FN_ file extensions with the wrong software program.

Quick Tip:   Incorrect FN_ file association errors can be a symptom of other underlying issues within your Windows operating system. These invalid entries can also produce associated symptoms such as slow Windows startups, computer freezes, and other PC performance issues.

Therefore, it highly recommended that you download WinThruster and scan your Windows registry for invalid file associations and other issues related to a fragmented registry.

If the FN_ file fails to open, it is highly likely that your system lacks the application needed to open FN_ files. It is common for several applications to share the same FN_ file extension label, so it could take some trial and error to figure out what application actually opens your file (if any).

Thus, I highly recommend that you contact the source of your file for more details on what program you need to open your FN_ file. This will save your a lot of time and headaches!

Remember to always take caution when opening files that come from unfamiliar sources or emails.

Is Your PC Healthy?

I always recommend to my readers to regularly use a trusted registry cleaner and optimizer such as WinThruster (Download) or CCleaner. Many problems that you encounter can be attributed to a corrupt and bloated registry.

Happy Computing! :)

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About the Author

Windows Wally is a helpful guy. It’s just in his nature. It’s why he started a blog in the first place. He heard over and over how hard it was to find simple, plain-English solutions to Windows troubleshooting problems on the Internet. Enter: Windows Wally. Ask away, and he will answer.

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