--- a/windows.rst	Thu Feb 25 10:39:23 2010 +0200
+++ b/windows.rst	Thu Mar 04 19:51:06 2010 +0200
@@ -1,5 +1,20 @@
 -*- outline -*-
 
+* Determining windows version.
+
+Run winver.exe: <Win> + R winver <RET>.
+
+Or type: <Win> + <Break>.
+
+Under cmd.exe use built-in command ver.
+
+For Win 2000 and upper check registry key:
+
+  cmd> reg query "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion" /v CurrentVersion
+
+To check 32/64-bit OS use PROCESSOR_ARCHITECTURE env var (it has such values:
+x86, AMD64, IA64).
+
 * XP.
 
 ** Check system files integrity.