Windows host process (Rundll32) has stopped working

Recently I came across a very strange video-related problem on my computer. Here’s what happened:

I had rendered a couple of MPEG clips from Premiere Pro CS4, and when I opened the folder with the rendered clip, almost immediately Windows would show the error message

Windows host process (Rundll32) has stopped working

At first, Windows pretended to “look for a solution” (yeah, sure), only to then find that the program had to be closed. And this error message appeared multiple times in quick succession.

Here are the screen shots (in German language):

I was puzzled – what the heck? I never had this happen before on my usually rock-solid editing suite. I had not made any changes to the system either, so what could be the reason? Well – after looking frantically for a solution, wading through numerous useless help forum posts, I think I found the cause of the problem on my own. If you are facing similar issues with your Vista installation, this may explain and fix your problem as well.

First, I thought this problem might be related to a corrupted/updated installation of Windows Media Player, but the files were playing fine. So I ruled that one out.

Next, I discovered that I could reduce the number of error message windows greatly by putting the Explorer view from “Large Symbols” to “Details”. That was a relief, but I was still getting an error message when I was just selecting one of the MPEG files with a single click (e.g. to rename the file). Weird. An error message just by selecting a file?

Well, I found that not every MPEG file would cause the problem. You see, I had rendered a couple of MPEG files before, and those files were sitting in the same directory as the MPEG files that were causing the problems. But I could select those older files, and the system was behaving just fine (no error message). Only the recently rendered clips were giving the errors. I figured that the error must be related somehow to the clips. And indeed, the only difference between two almost identical clips was the rendering size. The clip that was OK had been created in 1280×720 pixels using Premiere Pro’s default setting, while the clip that gave the error message was rendered with a custom sze of 720×405 pixels (which was 16:9 as well).

And I noticed what might actually be causing the problem: Explorer wants to show large preview icons for the files, but it is having problems with those customized file sizes, or with the thumbnails embedded in the clips. That’s the best explanation: when you open a folder with many customized MPEG clips and you use the large symbols view, then you will be bombarded by error messages as Explorer tries to display the large symbol for every file. And when you set the view settings to “details”, no large symbols will be accessed unless you select the file with a single click. In this case, however, Windows will still display a preview symbol in the lower left corner of the Explorer window:

The screenshot above shows an example of a clip that can be selected without generating an error message…

…while this screenshot shows a clip that does cause the error message to appear. (Note how Explorer can not display a preview of the clip, showing just a generic MPEG icon.)

This problem is perfectly reproducable on my system, so I think the error message is caused by a problem in Vista’s Explorer that for some reason can not access large symbol previews for MPEG files with customized sizes. It could be related to the MPEG video codec or the way Vista accesses the codec or the way Premiere Pro renders the video, but my investigation ends here. I don’t want to mess around with my codecs since the clips are playing fine both in Windows Media Player as well as VLC.

Possible ways to avoid the problem:

  • to render only standard-sized clips from Premiere
  • to put Windows Explorer view mode to “details”
  • to avoid playing files from Windows Explorer
  • to switch to a different file manager that does not try to show large symbols or does not give an error message when doing so

Hope this helps.

(Disclaimer: I am using Windows Vista 64 Home Premium SP2 on an Intel Core i7 920 with 2.67 GHz with 6 GB of RAM.)

One Response to “Windows host process (Rundll32) has stopped working”

  1. thank’s, this article help me very well !