etc/PROBLEMS: Update problems specific to MS-Windows.

etc/PROBLEMS

@@ -1917,6 +1917,16 @@ MSDN:
 includes a short description of MSLU and a link where it can be
 downloaded.
 
+** Emacs refuses to start on Windows 9X because ctime64 function is missing
+
+This is a sign that Emacs was compiled with MinGW runtime version
+4.0.x or later.  These versions of runtime call in their startup code
+the ctime64 function, which does not exist in MSVCRT.DLL, the C
+runtime shared library, distributed with Windows 9X.
+
+A workaround is to build Emacs with MinGW runtime 3.x (the latest
+version is 3.20).
+
 ** A few seconds delay is seen at startup and for many file operations
 
 This happens when the Net Logon service is enabled.  During Emacs
@@ -2084,7 +2094,7 @@ The function set-time-zone-rule gives incorrect results for many
 non-US timezones.  This is due to over-simplistic handling of
 daylight savings switchovers by the Windows libraries.
 
-** Files larger than 4GB report wrong size
+** Files larger than 4GB report wrong size in a 32-bit Windows build
 
 Files larger than 4GB cause overflow in the size (represented as a
 32-bit integer) reported by `file-attributes'.  This affects Dired as