Windows Error

Hi. I am new here and not very computer savvy - so asking me to change anything in my computer inner workings would be like asking me to start my computer on fire. :) I have been using Calibre for a couple years, just upgraded to the latest version, and now I get this error message:

Failed to start worker process
Traceback (most recent call last):
File "site-packages\caliber\utils\ipc\pool.py", line 197, in start_worker
File "site-packages\caliber\utils\ipc\pool.py", line 185, in create_worker
File "site-packages\caliber\utils\ipc\pool.py", line 71, in start_worker
File "site-packages\caliber\utils\ipc\simpe_worker.py", line 160, in start_pipe_worker
File "subprocess.py", line 710, in __init__
File "subprocess.py", line 958, in _execute_child (???????? WHAT!? - my comment)
WindowsError: [Error 2] The system cannot find the specified


PLEASE tell me how to fix this - in very plain language so I don't ruin my computer. I have an HP Windows 10 laptop, by the way.

Thank you.