Kevin, Thank you for the response and offer to help.
However, you failed to address my question: Why would the official Intel wireless adapter identification and update tool misidentify the adapter in my Dell Inspiron 15R 5537? (And the installed driver as well!?)
Might the confusion between the Intel and Microsoft adapter identification tools be relevant to the many connectivity problems on the Inspiron laptop?
This is the tool on the Intel site that I ran in response to Intel's advice: "The easiest way to identify your wireless adaptor...."
http://www.intel.com/p/en_US/support/detect/wireless
This was its finding [I made a screenshot; below is the text copied from it]:
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Product Detected: Intel Dual Band Wireless-AC 7260.
Current Driver Installed: 16.1.3.0
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The Tool also offered to download the latest driver:
"Newer Intel PROSET/Wireless WiFi
Connection Utility Available: 17.0.3"
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Of course, I chose not to download it! That's because (a) the Dell specs advertise the Inspiron 15R as having an Intel Wireless =N - 7260= adapter, (b) the built-in Windows 7 "Windows Network Diagnostics" tool and troubleshooter also says it is an N 7260 with a "Version 16.1.31" driver (NOT an Intel =AC 7260= with a version "16.1.3.0)," and (c) Win 7's Device Manager and systeminfo.exe show the same N 7260.
Before I go further, I'd like to know who or what to believe: the
official Intel wireless adapter identification and update tool, OR the Microsoft identification tools in Windows 7??? (If the Intel tool we ordinarily would rely on is flawed, an Intel tech supervisor ought to be informed, I would think.)
All of my troubleshooting so far implicates the installed Intel adapter hardware and/or firmware as the source of the connectivity problems. Remember: we have three other computers on the same wireless network, properly configured, working with no connectivity problems. That would exclude the router, AP, and other considerations from the list of suspects.
Marooned