all non-system cmd and powershell commands and scripts return error referencing quicktime- regardless of the content of the command or script

I'm not sure what caused this, but for the past few weeks every single cmd and powershell command I attempt to run, with the exception of built-in system commands, returns the same error:

\QuickTime\QTSystem was unexpected at this time.

I've tried deleting the sole user-made ps1 profile file, and cleared HKEY_CURRENT_USER\Console entries that sources I found while looking for a fix seemed to agree would reset both powershell and cmd to system defaults. The issue persists. Again: none of the commands or scripts mention quicktime at all. I have no idea what might have caused this and I'm now out of ideas on how to fix it.

Any suggestions on a fix? Is this issue familiar to anybody out there? I've put several hours into searching for solutions and not a single result has been relevant.

editing to clarify something: I don't believe this issue has anything to do with quicktime. The issue is that an unrelated program is for whatever reason being called on automatically every time a command or script is run. This is why my first troubleshooting attempts involved searching for a profile that I may have somehow set as the default.

PowerShell and CMD have almost nothing in common, except that they are both dependent on basic Windows mechanisms.

The most logical reason for such a general and common problem was therefore a problem with the PATH.

After verification, the poster found a problematic QuickTime entry. Removing the entry fixed the problem and restored both PowerShell and CMD to full function.