How To Fix “How do you want to open this file?” Popup on Windows 10 Startup

Whenever I start up my Windows 10 computer, I saw a popup screen that asks how do you want to open this file and a list of installed apps to choose from. I wasn’t sure what is the reason for this message. This might be the reason for a Windows upgrade or may a virus, malware, or something? I have installed antivirus, but It didn’t detect any problem. I see this whenever I start up or restart my computer.

See also: Fix Windows 10 startup blank screen

Fix “How do you want to open this file” startup Popup

I searched the internet to find the solution to this problem; someone says check your Startup folder.  \For sure anything that runs at the time of login will be in Windows Startup items, which make sense. But, I checked nothing was there. I managed to find out the solution on my own to stop popping out this screen every time when Windows startup. This is how fixed this error, let’s see how to disable popping up how do you want to open this file prompt on Windows 10 startup.

Locate this file

1. Once you see this screen on Windows 10 startup, select the Notepad app from the list of applications, as you can see below in the screenshot.
   
   NOTE: If you can’t see Notepad in the list then scroll down to view more apps or select the “Look for another app on this PC” option. In the next dialog, we will give the path to the application manually. So, go to “C:\Windows” and choose the “notepad.exe” file here.
   
2. The startup file will open in Notepad, and you will see the file contains text something like that
   Invalid number of parameters
Invalid number of parameters
ERROR: Invalid syntax.
Default option is not allowed more than '2' time(s).
Type "SETX /?" for usage.
Invalid number of parameters
3. Now, In the notepad click the File menu and then select the “Save As” option.
   
4. Doing that, you will let you know the file location that is trying to open itself on startup and ask you to choose an application. As you can see in the save as window, the path is “C:\users” and the file name is “M” which is suspicious to me.
   

Disable the file from Windows startup

We have already located the file and now it’s time to disable it from Windows 10 startup. To locate the startup items in Windows 10, you can use Task Manager as well.

1. Press Ctrl+Alt+Del keys combination from the keyboard and select Task Manager to open it. Tip: Another way to open it is just right-click on Taskbar and select Task Manager.
2. On the Task Manager window, click the “Startup” tab. Here, you can see all the apps and files that Windows run at startup. Find the file with the name “M” as I found this file name in step-4 above. This name might be different in your case so find accordingly.
   
3. Right-click on that file and select the “Disable” option from the menu. To confirm the path of this file, just right-click and choose the “Open file location” option. This will open the location in File Explorer, which is the same location that we already checked in step-4 above while searching the file.
   
4. Now, this file will not run on startup and also will not prompt you “How do you want to open this file?” screen. Reboot your computer and check it.

If you found this guide helpful and solved your problem, share your experience below in the comments, Windows version like Windows 8 or 10, Filename and location you saw, anything else that might be helpful for others.

Once, you disable this file from Windows Startup. You can delete it from the path where you found it. This file doesn’t seem harmful to me. But I am not sure about this at the moment.

Addition: One of our readers shares his experience and this might be helpful for you.

This is one of those problems where 3 or 4 different independent issues have come together to result in the problem you now see in front of you. This is why it doesn’t happen to everyone.

The solution above is a great start however it only goes 50% of the way to solving the problem. ie. It treats the symptom but does not get to the root cause (as TRICKYWAYS1 later asked). I had exactly the same problem and it took a little problem solving but I’ve found the root cause of my issue. Hopefully going through it here can also help solve your problem as well. (Please forgive me if this is wordy… I’m trying to give as much detail as possible to avoid confusion)

First, some of the independent factors (in my case) that came together to cause this problem;

a) You have a USER FOLDER that uses two words separated by a space – In my case “JEFF SMITH”

b) At some point in the past windows has left a file in your user directory named the first word of a user account – In may case “JEFF” (note: it had no extension, it was a very small log file likely left over from some windows system maintenance task)

c) Some other program has created a start-up key in the registry improperly formatted so that it actually (incorrectly) calls this file (from B above) by accident – In my case, MP3SkypeCallRecorder had the registry key C:\Users\JEFF SMITH\AppData\Local\MP3 Skype recorder\MP3SkypeRecorder.exe. Note the space in JEFF SMITH means that windows registry sees that SPACE as the end of the filepath. ie. It calls the file C:\Users\JEFF instead of the full file path. WHAT THE REGISTRY KEY NEEDS ARE QUOTATION MARKS ( “ ) SO THAT IT SEES THE ENTIRE ADDRESS PATH. ie. “C:\Users\JEFF SMITH\AppData\Local\MP3 Skype recorder\MP3SkypeRecorder.exe” Note the VERY subtle difference there with the quotation marks.

d) The result being that windows is trying to open C:\Users\JEFF. Windows don’t recognize this file type so it brings up the “How do you want to open this file?” dialogue which is the cause of our annoyance.

So, my steps to solving this problem are first, identifying the offending file to confirm (b), then confirming that there is an offending start-up entry, then finding and fixing the bad registry key. Don’t worry, it’s not that hard – BUT IT DOES REQUIRE A VERY BASIC REGISTRY EDIT if you are up for it. TRICKYWAYS has done the first part – you can use their method, or my way is slightly different but achieves the same thing. BUT we ARE NOT going to disable it in TASK MANAGER > START-UP.

1. When the “How do you want to open this file?” dialog comes up on login select NOTEPAD. The content will vary. But in Notepads title bar you will see the name of the file – In my case “JEFF – Notepad”. So the filename is { JEFF }.
2. Open TASK MANAGER > START-UP tab and look for any unusual entries. – In my case it was obvious. There was an entry simply called “JEFF”. DON’T disable it. Instead [Right Click] the entry, select OPEN FILE LOCATION.
3. This will open Explorer to the file location. This hopefully confirms (b) above. – in my case, it opened C:\Users which contained my USER FOLDERS (Default, Jeff Smith, Public etc) and the file { JEFF }. This was the file that was trying to be opened at login.
   Note: This is where Trickyways above finishes. But I want to find out why this file is in the Start-up menu in the first place.
4. Open RUN > REGEDIT (or get into the Registry Editor any one of the other dozen ways you can find online)
5. As it appears user account specific I tried first HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
6. Look in there at the start-up keys. You will note that most of the file path strings have quotation marks ( “ ) around the path which makes windows read the entire path. However, there was one that did not. C:\Users\JEFF SMITH\AppData\Local\MP3 Skype recorder\MP3SkypeRecorder.exe  which resulted in windows trying to open C:\Users\JEFF from step 3. above.
7. [Double Click] the key name. This will allow you to edit the string. Simply add quotation marks ( “ ) to either end of the filepath. Select [OK]. My entry now reads “C:\Users\JEFF SMITH\AppData\Local\MP3 Skype recorder\MP3SkypeRecorder.exe” Note the VERY subtle difference there with the quotation marks.
8. Re-open TASK MANAGER > START-UP tab. You will note that the faulty entry has disappeared and the correct start-up program has now re-appeared (you may not have even noticed that that program was not starting on login – I hadn’t realized until I found this issue then thought “Oh yeah, MP3 Skype Recorder should have been starting on login but it wasn’t.”)
9. Hopefully problem solved.

EXTRA CREDIT: If you can’t find problem registry keys at step 6, try the following alternate registry paths:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunOnce

Or the following folders checking for entries there:

C:\Users\Username\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup

C:\ProgramData\Microsoft\Windows\Start Menu\Programs\StartUp

It took me a little while to nut out, but this solved my problem. I certainly hope this can help someone else.