Rick, can you share how to fix this? There are numerous threads on it and this is the first one where someone said they found something that worked. I have the window come up asking me to "start tour" of my new Acrobat Reader DC also and it's slowing my work flow.
Dear tpa72,
No problem. A member of the adobe forums wrote the following:
"For the issue with the welcome card.
Would request you to run the reg file using these lines and let me know if this resolves issue for you.
[HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\DC\FTEDialog]"iFTEVersion"=dword:0000000a
"iLastCardShown"=dword:00000000"
I then ran regedit, that is in windows 7, start -> run -> type in regedit and hit enter/OK.
Here is a screen shot of the registry before the adobe reader dc splash screen fix:

I changed the iFTEVersion value from a 5 to an a. I then created a value called "ILastCardShown" (REG_DWORD) and set it to "0" (without the parenthesis). Here is the screen shot after the adobe reader DC splash screen registry fix suggested by the forum member.

After I made the registry changes I closed the registry window. I then clicked on .pdf file from windows explorer, the .pdf file popped up with out the the splash screen!!! Hope this helps. Cheers. 
Rick Ambrosino