It turns out it was a bad wireless card.  I replaced the original wireless adapter with the one Dell suggested. www.dell.com/.../networking Now it is working excellent.  5 bars, when usually 3 (without the extender).  Signal is excellent (when before it was good) Tip: download the appropriate drive before installing.  For the card that Dell recommended, the driver was: www.dell.com/.../DriversDetails When i installed the new adapter, I could not connect to the internet.  The original driver did not work with the new card.  I had to connect the desktop to a range extender via ethernet, download the correct driver, and then install it.  When installed, it worked great.
I have scoured the internet and Dell support webpages.  I love my Dell XPS 8700, but the recurrent problem I have had is with internet connection.  There are regular and persistent drops and slowings.  I will reset the adapter (Dell Wireless 1704 802.11b/g/n (2.4GHz)) and it will pick up for 10-20 seconds and then drop again.  On the same desk I will run my laptop (Dell XPS 12) and simultaneously run speedtest.net.  And they will display vastly different results (not all of the time, but most of the time). I have the latest driver for the Dell Wireless 1704 802.11b/g/n (2.4GHz). I have done some of the instructions on this thread en.community.dell.com/.../19668056. Is there a way to test the card to see if it is faulty?  Can I simply purchase a new one and replace it?  (I am moderately tech savvy.)  I do run the DW WLAN Card Utility and found that "SPROM Format Validation" test Failed.  A google search and Dell website KB search do not give answers. I have had uverse come and replace the router.  No other people in the household have had problems.  I have even placed a range extender and have 5 bars. Any advice or guidance would be most welcome. Cheers, Chris Houston, TX
Concern that Dell Wireless 1704 802.11b/g/n (2.4GHz) is a dud ("SPROM Format 
Validation" test Failed)