Why is splwow64.exe being created when running Office 64-bit Word or Execl?

Question

Why is splwow64.exe being created when running Office 64-bit Word or Execl?

Anonymous

The latest version of the Office 64-bit updates available for Office version 2016, 2019, 2021, O365 all exhibit a new behavior that applies only to Word and Excel applications. These 64-bit process are now creating (launching) splwow64.exe as a sub process.

For interactive desktop usage this appears not to be an issue but when you are using Word/Excel together with COM automation using the PrintOut method and you have a printer set to RAW (bypassing the print queue) then either Word or Excel will crash with printer failed to initialize on calling the PrintOut method.

This is a new behavior that started at some point but is definitely part of the latest Office update.

Is there a way to stop the splwow64.exe from being launched? It should only be launched with the Office products are 32-bit.

Locked Question. This question was migrated from the Microsoft Support Community. You can vote on whether it's helpful, but you can't add comments or replies or follow the question.

0 comments

Answer accepted by question author

4 additional answers

Answer 1

Okay for all of us that are hitting this issue, the reason is applications can now add to their manifest that they support application driver isolation. The office products like Word and Excel now have this in their manifest.

So to fix this problem, and so COM automation works properly, you need to disable 'Isolate print drivers from applications' as shown below.

Answer 2

I did some low level debugging of Word 64-bit to determine who is creating the splwow64.exe.

It's the AppVIsvSubsystems64.dll, but I don't know why it's doing this when it should not be.

This is the same issue with Excel 64-bit.

Does anyone know why this is now happening when it should not be?

Answer 3

Jay, I am totally aware of the purposed of splwow64.exe. I develop print drivers are as business and having been doing this for over 25-years. I know that for 32-bit process on a 64-bit Windows OS, splwow64.exe is the bridge between 32-bit process and the 64-bit printing subsystem.

However were talking Office 64-bit on Windows 64-bit. Splwow64.exe has never been using in this environment and is only showing after a specific Office patches for Word and Excel only. All other Office 64-bit applications (PowerPoint, Outlook, etc) are behaving correct, no splwow64.exe is created as expected.

I believe this is a new really bad bug introduced by an Office patch.

Answer 4

The only suggestion in the Answers forum thread that Tin Zhang cited was to disable the spooler service, which would prevent printing altogether. That isn't likely to be of any use.

It appears that Microsoft has decreed that splwow64.exe will be started every time a document is sent to the spooler service, regardless of whether the printer driver to be used is 32 or 64 bits. I haven't found any suggestion on the web that this can be prevented. Removing or renaming the splwow64.exe file just results in an error.

I can offer only a "maybe this will work in your environment" suggestion. It's based on the article https://support.microsoft.com/en-us/topic/splwow64-exe-process-does-not-end-after-a-print-job-finishes-in-windows-8-or-windows-server-2012-f787d678-0a9d-43c0-4ff1-e17a2a50abee and on the forum thread https://answers.microsoft.com/en-us/windows/forum/all/splwow64exe-does-not-end-after-a-print-job-in/e09966f6-07ba-4eef-907a-daf5aebb65f2 which indicates that the procedure still works in Windows 10.

The idea is this: By default, splwow64.exe continues to run for 2 minutes after a print job finishes, to avoid a delay in restarting it if another job is ready to start. For some reason that isn't given, that may cause the code to hang. The articles describe how to add a registry value named splwow64timeoutseconds to change how long the delay lasts. I suggest setting it to 1 or 2 seconds. (Setting it to 0 restores the 2-minute timeout.) If I'm right, the program will exit before the next document arrives, avoiding the hang.

I've tried a 2-second timeout (with Word from Microsoft 365 on Windows 10), and the Task Manager shows the program disappearing from the process list 2 seconds after a print job ends. Probably 1 second would be better.

Answer 5

Dear Robert Massart,

Good day! Thank you for posting to Microsoft Community. We are happy to help you

According to your description, we understand that you found splwow64.exe would pop up when running 64-bit Office applications, which you think may be related to the latest updates of Office.

Splwow64.exe is a Windows core system file which runs in the background services of your operating system Task Manager lists it as the “Printer driver host for 32-bit applications.” In other words, splwow64.exe allows 32-bit applications to connect with the 64-bit printer spooler service on x64 Windows builds. If you want to disable this process, you can refer to this thread first: Word 64bit wants to print under splwow64.exe - Microsoft Community

We also think this phenomenon is unreasonable, but I don't seem to have encountered the same phenomenon in our tests here, so I don't think it's necessarily the Office application updates that cause this phenomenon. Howver, to further reduce this phenomenon, we kindly recommended you can raise a service request in Microsoft 365 admin center, which the support there has the related permission and resource to help you check from the backend. At the same time, they can help you further analyze this phenomenon by helping you remotely obtain the activity logs of your application.

Sincerely,

Tin | Microsoft Community Moderator

Share via

Why is splwow64.exe being created when running Office 64-bit Word or Execl?

4 additional answers