Entry Point CopyFile2 not located in KERNEL32.dll

[JohnB_Bristol]

Hi.
Recently (since about 20 April 2025), Adobe Acrobat Reader repeatedly displays an error message:

I'm using a PC running Windows 7 Pro ... and the version number of Acrobat Reader is 2025.001.20474.
I've uninstalled and then reinstalled Acrobat Reader . . . but the error messages still occur.
Any clues as to how to solve this.....?
Many thanks.

[AnandSri]

Hello John!

I hope you are doing well, and thanks for reaching out.

This error occurs because the CopyFile2 function is part of the Windows API introduced in Windows 8 and later. You're using Windows 7, which does not support this function. The version of Adobe Acrobat Reader 2025.001.20474 you installed is built for Windows 10 or newer and is not compatible with Windows 7. See this article for the technical specification of Acrobat Reader: https://adobe.ly/3EWAxF8

Recommended Solutions: 
1. Update Windows to the Latest Version: The CopyFile2 function is not available in older versions of Windows. Ensure you're running a supported version of Windows (preferably Windows 10 or later) and that all updates are installed:

Go to Settings > Update & Security > Windows Update. Click Check for updates and install any available updates.

2. Install Microsoft Visual C++ Redistributable Packages: Missing or outdated Visual C++ Redistributable packages can cause DLL-related errors. Install the latest supported versions: Microsoft Visual C++ Redistributable latest supported downloads.

See this article for more details: https://adobe.ly/44YulqO

Note: The above suggested steps may or may not work depending on the app's compatibility with the operating system.

I hope this helps.

Thanks,

Anand Sri.

[JohnB_Bristol]

Hi Anand Sri.
Thankyou for getting back to me so quickly.  I appreciate your help.

I'm running Windows 7 because newer versions of Windows won't run some of my older software.
I have unstalled Acrobat Reader version 2025.001.20474 ... and have now installed version 2025.001.20467 which Adobe says is the latest version for Windows 7 UK English . . . and I have downloaded vc_redist.x64.exe from Microsoft and run it (which required me to first uninstall the version already on my PC because it was more recent) . . . but the problem in Acrobat Reader still persists.
Do I have to put up with Acrobat Reader displaying the error message  -  or is there a way to fix this..?

With many thanks.  🙂

[JohnB_Bristol]

I'm STILL getting the error messages.
Is there a way to fix this..?

[AnandSri]

Hi John!

Thank you for sharing additional information. Create a test user profile with full admin rights, install Acrobat Reader and check if you still get the same error message. Also, are you running a 32-bit Windows or a 64-bit Windows?

Let us know how it goes.

~Anand Sri.

[JohnB_Bristol]

Hi Anand Sri.
Thankyou.  I'm running Windows 64-bit.
I created a test user profile, with full admin rights, and installed Acrobat Reader in the test user set-up, as you suggested . . . and it worked without any problem!  Went back to my own set-up and it still has the problem there.  So maybe you're onto something here!  🙂

Any suggestions as to what I should do next would be greatly appreciated.  🙂

[AnandSri]

Hi John!

I am happy to know that it worked on the new user profile, and thanks for testing that out. Your result strongly indicates that the issue lies within your original Windows user profile, not the Acrobat Reader installation itself.

This happens because user profiles can accumulate corrupt permissions, damaged registry keys, or conflicting user-specific settings, especially if the profile has been used for a long time or has experienced failed updates. Acrobat Reader depends on these settings (like access to temp folders, registry keys under HKEY_CURRENT_USER, etc.) to function correctly. Try installing the Microsoft Visual C++ Redistributable Packages, ensure all the mandatory and optional updates of the operating system are installed, and check again in the old user profile. 

• Check Permissions:

  • Ensure your user account has full control of folders under:

    • %APPDATA%\Adobe

    • %LOCALAPPDATA%\Adobe

• Clear Temporary Files:

  • Run Disk Cleanup or manually clear %temp%.

If the problem continues in your current profile but not in the new one, the most stable fix is to migrate to the new profile:

• Transfer files from your old profile (Documents, Desktop, etc.) to the new one.

• Set the new profile as your main user.

I hope this helps.

Thanks,

Anand Sri.

[JohnB_Bristol]

Hi again Anand.
I ran Disk Cleanup ... and restarted my PC ... which took over an hour ... and now I find that (as well as the error messages about KERNEL32.dll stil appearing) I now have an additional problem for some (but not all) of my pdf files when I try to read them:  Acrobat Reader says: "There was an error opening this document. Access denied" !!
Oh dear.

So ... I altered the permissions for one of the files I'm now unable to read ... and noticed a user-name "RESTRICTED" which I'd previuosly been unaware of ... and it's now readable ... but I have THOUSANDS (!) of pdf files and would have to check ALL of them to see whether or not their permissions still allow me to read them.

Help!  Please.

[AnandSri]

Hi John!

Because your test profile worked, but your long‑used profile still shows “Access denied,” the root cause isn’t Acrobat itself—it’s your user‑profile’s file permissions and sandbox settings. When you ran Disk Cleanup, Windows reset or removed inherited permissions on your PDF folders, leaving a mysterious “RESTRICTED” user and blocking Reader’s sandbox from opening them.

• Open an elevated Command Prompt (Run as administrator).

• Run these commands against the root folder where your PDFs reside (for example D:\PDFs😞

takeown /F "D:\PDFs" /R /D Y
icacls  "D:\PDFs" /grant "%USERNAME%":(OI)(CI)F /T
icacls  "D:\PDFs" /reset /T

• takeown makes you the owner of every file/folder.

• icacls … /grant gives your account Full control, propagating to subfolders (OI=object inherit, CI=container inherit).

• icacls … /reset restores default inherited ACLs.

This will remove the “RESTRICTED” entries and re‑enable normal access for your user, SYSTEM, and Administrators.

Even with correct permissions, Acrobat may still block files from unexpected locations. To allow your PDFs to open:

• In Acrobat Reader, go to Menu> Preferences > Security (Enhanced)

• Uncheck “Enable Protected Mode at startup” (or set Protected View to “Off”)

• Or under Privileged Locations, click Add Folder Path and add your PDF root folder.

• Open a formerly blocked PDF.

• It should now load without “Access denied.”

If the issue still persists with the current user profile, please switch to the new user profile which you created, and migrate the data as suggested earlier.

Thanks,

Anand Sri.

[JohnB_Bristol]

Thanks Anand.

As it happens . . . in the meantime, I'd discovered that by copying all of the thousands of sub-folders and files from my previous location (e.g. a folder called "PDF Files") to a brand new folder (e.g. called "PDF Files NEW"), ALL of the files are now readable.  Yay!  I then deleted the old "PDF FIles" folder and re-named the new folder from "PDF FIles NEW" to "PDF Files".

I still have the KERNEL32.dll error messages appearing when I open some (but not all) of my pdf files.

I am NOT inclined to move everything to a new (and differently-named) user profile  -  mainly because of concerns that this action might well cause problems with OTHER software I use (such as my daily encrypted backup system).

It's a shame that there's not an easy fix, such as just amending a Registry Entry item or two, to stop the KERNEL32.dll problem.

Thankyou for your help, Anand.

[JonJ_UK]

Strangely enough I have exactly the same CopyFile2 problem which arrived at pretty much the same time as JohnB's o/p. I'm also running W7 (32bit in my case). The error message comes up three times in succession, annoyingly. I'm wondering if there's something in common here, investigating and will report back.

[JohnB_Bristol]

Hi again Anand.

It does seem (see other comments here and also searching on the internet) that Copyfile2 was introduced in Windows 8  -  so that's maybe why the version of Reader meant to be suitable for Windows 7 is causing problems for Windows 7 users.

So ... do you know is there's:

(1) a previous version of Reader which WILL work in Windows 7 available to download (and which can be set to NOT update itself to the 'faulty' version of Reader..?

or

(2) are there any plans being worked on to fix the 'faulty' Windows 7 verison of Reader..?

With many thanks.

[AnandSri]

Hi John!

Thank you for sharing additional details, and I really appreciate your time and cooperation on this. 

As you rightly mentioned, the CopyFile2 API was introduced with Windows 8, and is not available in Windows 7. The latest Adobe Acrobat Reader versions (post mid-2023 updates) use system callsCopyFile2, which leads to compatibility issues when running on Windows 7, even though the installer may still allow it. This is why you're seeing the “entry point CopyFile2 could not be located in Kernel32.dll” error, which is often repeated multiple times when opening PDF files. 

However, as shared earlier, Adobe no longer officially supports Reader for Windows 7, so older builds are archived due to security and compatibility concerns. If possible, upgrade your machine to Windows 10 or Windows 11. There is little that can be done for unsupported operating systems. Rolling back to any previous version may pose security and vulnerability issues, which Adobe does not recommend.

You may download the previous version from this URL: https://adobe.ly/43zMRUn;

Disable Auto-Updates: Open Reader > Menu > Preferences > Updater. Set to “Do not download or install updates automatically”

:warning: Important: Use this rollback only if you fully understand the security implications of running outdated software. Keep the system offline or sandboxed if possible.

~Anand Sri.

[JohnB_Bristol]

Hi Anand.

Thankyou for the information . . . but my bowser says that the link you provided for the previous working version for Windows 7 is "403 Forbidden. Access to this resource is denied".

Is there an alternative link you can share..?

Many thanks.

[AnandSri]

Hi John!

Sorry for the typo, adding a ; at the end of the link creates a problem and throws an error. Here is the updated link: https://adobe.ly/4keXna1

Thanks,

Anand Sri.

[JohnB_Bristol]

Hi Anand.

Thanks for the corrected link.

The only option this link presents me with for Windows 7 English (UK) is version 2025.001.20467.  This is the same version I downloaded on 6 May  -  although (curiously!) when I open Reader, it says it's version 2025.001.204674.

Before I do so ... do you think if I uninstall Reader and reinstall this 20467 version, it will help..?

With thanks,

John

[JonJ_UK]

JohnB,

This may seem to be going off at a tangent but I was wondering, did you perhaps have installed and then unistall HMRC Basic PAYE Tools on your PC shortly before this issue arose?  I think that might have been using Microsoft Visual C++.

[JonJ_UK]

JohnB, Anand,
I tried both the repair and the uninstall / reinstall of AR and it didn't fix anything. In fact I found I was unable to re-install AR as it first gave an error message that it could not patch a file (ignored) and secondly failed to complete and rolled back. I then attempted to do a windows system restore from two available prior restore points and that failed on several attempts, but for unknown reasons AR which I'd previously removed reappeared regardless! But unfortunately it still has the CopyFile2 error issue, which happens three times on start-up of AR.

I've subsequently installed the latest version of Microsoft Visual C++ but that didn't fix it either.

[AnandSri]

Hi @JohnB_Bristol!

Yes, you can install the version listed on the link. 

@JonJ_UK! As shared earlier, the error is related to Windows. If you create a new user profile with full admin rights, the Acrobat Reader may work. However, there isn't much that can be done from our end on an unsupported Windows. The solution is to upgrade the OS to the latest version.

Thanks,

Anand Sri.

[JohnB_Bristol]

Hi again Anand.

I uninstalled (again) Reader ... and reinstalled it (again) using your amended link.

It's version 2025.001.20467 (again).

It has the KERNEL32 problem (again).

Also, there is NO Menu > Preferences > Updater option!  There are plenty of other options, but not an Updater option!

Is there an older (pre- April 2025) version available to download which does actually work in Windows 7..?

JohnB

[loyal_curiosity4109]

That error likely means the latest Reader version is using system calls not supported in Windows 7 CopyFile2 was introduced in Windows 8 [removed third party link]  Rolling back to an earlier Reader version might help.

[rick_4271]

I was having the same issue with Windows 7. The way I corrected it was to uninstall Adobe. Then re-ran the adobe install exe, but before running it, I opened the file properties and selected compatibility
Check the box, Run this program in compatibility mode for:
Select [Windows 7] in the drop down box
Select OK
Then run the AcroRdrDC2400220857_en_US.exe or similar program
After doing this, I no longer saw the error messages.

[JohnB_Bristol]

Hi Rick.

Great ... I'm glad this worked for you.

I followed your instructions ... and at first all was okay ... but then (after a minute or two) Reader said it was updating ... after which , the KERNEL32 messages problem re-occurred!

There seems to be no option available to me to stop Reader from downloading updates.  Do you know how to prevent it from automatically updating?

With many thanks,

John

[rick_4271]

Adobe updated for me yesterday and now I'm getting the messages again too. Sorry about that, I don't see a way to prevent Adobe reader updates.

[tdhofstetter · Accepted solution]

rick_4271: that's not too hard. Go into your Services and disable Adobe's updater service.

To all else... AnandSri has been leading you down a tunnel of misinformation. CopyFile2 isn't called by Adobe Reader at all. It's called only by AdobeCollabSync, which is a different program that Adobe Reader infuriatingly tries to run because it thinks that you want to use your PDFs collaboratively with other people across the Internet.

Which nearly nobody actually does.
Further infuriatingly. you can't just disable AdobeCollabSynk by deleting or renaming it. Reader gleefully just downloads another copy. against your wishes. Your best bet is to close all Adobe programs, wait until all the Adobe processes are gone from your TaskMan, delete AdobeCollabSync.exe, then immediately create (or copy in) an empty text file that has been renamed AdobeCollabSync.exe, then lock that file so it cannot be replaced.

To lock the file, first set its permissions to read-only. Then go into Permissions and add yourself with full control and also add Administration with full control, then turn off Permission Inheritance and remove all permissions for System. You want to personally be the only one in control of this file's existence.

Sometimes you have to throw rocks to kill despotic giants.