Troubleshooting: 5.0.0+ won't run under Windows 7

Troubleshooting.md

@@ -45,6 +45,7 @@ Then to add it back :GenTocRedCarpet
     * [EDMarketConnector needs permission to use shortcuts](#edmarketconnector-needs-permission-to-use-shortcuts)
 * [Program won't start](#program-won-39-t-start)
     * [Re-running application does nothing](#re-running-application-does-nothing)
+    * [Application won't run under Windows 7](#application-won-39-t-run-under-windows-7)
     * [Last logged "Locale LC_ALL: ..."](#last-logged-quot-locale-lc_all-quot)
 * [Problems with Frontier Authentication](#problems-with-frontier-authentication)
     * [App is stuck on 'Logging in...'](#app-is-stuck-on-39-logging-in-39)
@@ -364,6 +365,61 @@ because a process (which can't be EDMarketconnector.exe because you already
 checked that) has the file open then you'll need to resolve that in order for
 EDMarketConnector.exe to run again.
 
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+## Application won't run under Windows 7
+This application is no longer supported on Windows 7.
+
+Development of this application tends to track the latest stable release of 
+Python as per https://www.python.org/downloads/windows/ . For the 5.0 
+series of releases we are using Python 3.9 which no longer supports Windows 
+7 (it does still support Windows 8, 8.1 and all versions of 10).  
+
+Trying to run either EDMarketConnector.exe or EDMC.exe (the command-line 
+tool we provide) will result in an error like:
+
+    "api-ms-win-core-path-l1-1-0.dll" is missing
+
+That DLL file is not part of Windows 7, being added from Windows 8 onwards. 
+Python 3.9 relies on it, hence no support under Windows 7.
+
+NB: Versions of this application prior to 5.0.0 will work poorly, at best, 
+against Elite Dangerous Odyssey.  We provide no support for them under that 
+version, and that includes the older 'Horizons' version once it has been 
+updated to the newer Odyssey code later in 2021.
+
+Until we use any Python feature (such as forthcoming 'matches' in Python 3.10)
+you can attempt to [run from source](https://github.com/EDCD/EDMarketConnector/wiki/Running-from-source)
+under Python 3.8, but we make no guarantees about this working now, or in 
+the future.  Use the latest 3.8 version from [python.org](https://www.python.org/downloads/windows/).
+You need the 32-bit version.
+
+As per "[Windows 7 support ended on January 14, 2020](https://support.microsoft.com/en-us/windows/windows-7-support-ended-on-january-14-2020-b75d4580-2cc7-895a-2c9c-1466d9a53962)"
+, Windows 7 is no longer supported by Microsoft:
+
+<blockquote>Microsoft made a commitment to provide 10 years of product support 
+for Windows 7 when it was released on October 22, 2009. This 10-year period
+has now ended, and Microsoft has discontinued Windows 7 support so that we can
+focus our investment on supporting newer technologies and great new
+experiences. The specific end of support day for Windows 7 was January 14,
+2020. Technical assistance and software updates from Windows Update that help
+protect your PC are no longer available for the product. Microsoft strongly
+recommends that you move to Windows 10 to avoid a situation where you need
+service or support that is no longer available.
+</blockquote>
+
+We assume that if you have the funds to pay for [Windows 7 Extended 
+Security Updates](https://docs.microsoft.com/en-us/troubleshoot/windows-client/windows-7-eos-faq/windows-7-extended-security-updates-faq)
+then you could as easily buy new Windows 10 capable hardware or purchase a 
+standalone copy of Windows 10 to use.
+
+Despite what MicroSoft says on that page about support ending you should 
+still be able to [upgrade to Windows 10 for free](https://techviral.net/upgrade-windows-7-to-windows-10/).
+    
+
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