fix computer errors

I have an on-going “rundll32.exe has stopped working” error.
There are a lot of forum topics on this. But none of them help me. For starters, I don’t have Nero. I have Realtek Audio, but it’s the Realtek HD Audio Manager, not the Realtek AC97 audio driver, so ‘Soundman’ doesn’t even exist in my registry. Also, the error doesn’t occur when I open up a folder with videos, or have any connection to opening folders containing videos, so turning off thumbnail previews won’t work either.
Rather, the error occurs 2, usually 3, but up to 7 times a day, often after returning from not using my computer for a while. Most of the time, when I return to my computer after having it locked down but still running, I type in my password, unlock it, and have 1 to 3 errors sitting on top of each other. The number of errors may be related to how long I leave my computer, but I haven’t made sure of this. The only time that the error occurs while I’m actually using my computer is when I hit ctrl-alt-delete, then select “Start Task Manager” from the options (“Lock Computer”, “Switch Users”, etc). This, however, only happens sporadically as well. There’s nothing I can do to get the error every time. If I try opening Task Manager the same way again, it’s fine. Nothing has ever stopped working in correlation to this error. I just hit ‘Okay’ and keep working. I’ve done system restores, too, and nothing helps. Any ideas out there as to what this could be?

Getting tis rundll error message after startup. My computer clean of viruses I’ve checked with Malwarebytes Antimalware and Superantispyware.