bpo-36264: Don't honor POSIX HOME in os.path.expanduser on Windows (GH-12282)

diff --git a/Lib/ntpath.py b/Lib/ntpath.py
index 11bb297..b5e1d12 100644
--- a/Lib/ntpath.py
+++ b/Lib/ntpath.py
@@ -299,9 +299,7 @@
     while i < n and path[i] not in _get_bothseps(path):
         i += 1
 
-    if 'HOME' in os.environ:
-        userhome = os.environ['HOME']
-    elif 'USERPROFILE' in os.environ:
+    if 'USERPROFILE' in os.environ:
         userhome = os.environ['USERPROFILE']
     elif not 'HOMEPATH' in os.environ:
         return path