diff --git a/runtime/doc/os_dos.txt b/runtime/doc/os_dos.txt
index 925c7e0..b45cb08 100644
--- a/runtime/doc/os_dos.txt
+++ b/runtime/doc/os_dos.txt
@@ -17,6 +17,7 @@
 7. Interrupting			|dos-CTRL-Break|
 8. Temp files			|dos-temp-files|
 9. Shell option default		|dos-shell|
+10. PowerShell			|dos-powershell|
 
 ==============================================================================
 1. File locations					*dos-locations*
@@ -297,8 +298,46 @@
 	<shell> -c "command name >file"
 For DOS 32 bit, DJGPP does this internally somehow.
 
-When starting up, Vim checks for the presence of "sh" anywhere in the 'shell'
-option.  If it is present, Vim sets the 'shellcmdflag' and 'shellquote' or
-'shellxquote' options will be set as described above.
+When starting up, if Vim does not recognise a standard Windows shell it checks
+for the presence of "sh" anywhere in the 'shell' option.  If it is present,
+Vim sets the 'shellcmdflag' and 'shellquote' or 'shellxquote' options will be
+set as described above.
+
+==============================================================================
+10. PowerShell						*dos-powershell*
+
+Vim also supports Windows PowerShell.  If 'shell' has been set to
+"powershell.exe" at startup then VIM sets 'shellcmdflag', 'shellxquote',
+'shellpipe', and 'shellredir' options to the following values:
+
+'shellcmdflag'	-Command
+'shellxquote'	"
+'shellpipe'	2>&1 | Out-File -Encoding default
+'shellredir'	2>&1 | Out-File -Encoding default
+
+If you find that PowerShell commands are taking a long time to run then try
+setting 'shellcmdflag' to "-NoProfile -Command".  Note this will prevent any
+PowerShell environment setup by the profile from taking place.
+
+If you have problems running PowerShell scripts through the 'shell' then try
+setting 'shellcmdflag' to "-ExecutionPolicy RemoteSigned -Command".  See
+online Windows documentation for more information on PowerShell Execution
+Policy settings.
+
+The 'shellpipe' and 'shellredir' option values re-encode the UTF-16le output
+from Windows PowerShell to your currently configured console codepage.  The
+output can be forced into a different encoding by changing "default" to one of
+the following:
+
+	unicode		 - UTF-16le (default output from PowerShell 5.1)
+	bigendianunicode - UTF-16
+	utf8		 - UTF-8
+	utf7		 - UTF-7 (no-BOM)
+	utf32		 - UTF-32
+	ascii		 - 7-bit ASCII character set
+	default		 - System's active code page (typically ANSI)
+	oem		 - System's current OEM code page
+
+Note Multi-byte Unicode encodings include a leading BOM.
 
  vim:tw=78:ts=8:noet:ft=help:norl: