Trouble using K4MobiDeDRM_v03.8_plugin.zip with Calibre

[nookyuser]

I downloaded a Kindle book to Kindle for PC v. 1.8.3. I loaded the K4MobiDeDRM_v03.8_plugin.zip (included in package tools_v4.8) into Calibre v0.8.41 using the readme information included with the K4 package. I saw the part about adding a Kindle PID to the configuration of the plug-in but did not do that since it said it was not needed if using Kindle for PC.

I opened Calibre and attempted to Convert Books but received the message "Cannot Convert. This book is locked by DRM". In the readme under further troubleshooting, it suggested loading the book from the command line use calibred which I did. The information returned is as follows:

calibredb add B006MAWJPG_EBOK.azw
is not a valid Kindle serial number or PID.
K4MobiDeDRM v0.3.8: Calibre configuration directory = C:\Users\LJFord\AppData\Roaming\calibre
MobiDeDrm v0.32. Copyright 2008-2011 The Dark Reverser et al.
MOBI header version = 6, length = 232
Extra Data Flags = 3
Running file type plugin K4PC, K4Mac, Kindle Mobi and Topaz DeDRM failed with traceback:
Traceback (most recent call last):
File "site-packages\calibre\customize\ui.py", line 148, in _run_filetype_plugins
File "calibre_plugins.k4mobidedrm.__init__", line 80, in run
File "calibre_plugins.k4mobidedrm.kgenpids", line 263, in getPidList
File "calibre_plugins.k4mobidedrm.k4pcutils", line 177, in getKindleInfoFiles
WindowsError: [Error 2] The system cannot find the file specified
Backing up metadata
Notifying calibre of the change

I can open the book in the Calibre viewer and in Kindle PC but cannot convert the book to epub or pdf format as I wanted. Thank you in advance for any help you can provide...this process is new to me and I tried to provide as much detail as possible.