Error opening file for writing - My Digital Editions - welcome.epub

I did a complete, and I mean complete uninstall of Adobe Digital Editions.  Using Geek uninstaller, I cleaned out everything.  The My Digital Editions folder had a few files in it.  I backed up the books, and used Unlocker to delete all the rest.  Did a clean install and everything works fine.

I think I found my own solution to this issue.  It seems to be caused by reinstalling Digital Editions after uninstalling an older version.  Before trying to install the package again, I downloaded a fresh copy of the welcome.epub file.  You can find this on the Adobe Digital Editions Home / Download Adobe Digital Editions page under Additional Downloads.  It's disguised, so it reads Download Getting Started with Adobe Digital Editions (EPUB, 55 KB): http://wwwimages.adobe.com/content/dam/Adobe/en/products/digital-editions/assets/welcome.epub.

Create -- if you don't have it already -- a folder under C:\Users\YourUserID\Docs\ (substituting your own User ID for YourUserID, of course) called My Digital Editions.  Copy the welcome.epub file you downloaded into the new folder.  It seems that since I moved My Documents to another drive, Adobe couldn't find its Getting Started book during the installation.

This work-around worked for me; no guarantee it will solve the issue for everyone.

--Fred