Implemented IsOS function.

include/shlwapi.h

diff --git a/include/shlwapi.h b/include/shlwapi.h
index 47328a6..eab5c09 100644
--- a/include/shlwapi.h
+++ b/include/shlwapi.h
@@ -939,6 +939,49 @@
 
 HRESULT WINAPI DllInstall(BOOL,LPCWSTR);
 
+
+/* IsOS definitions */
+
+#define OS_WIN32SORGREATER        0x00
+#define OS_NT                     0x01
+#define OS_WIN95ORGREATER         0x02
+#define OS_NT4ORGREATER           0x03
+#define OS_WIN2000ORGREATER_ALT   0x04
+#define OS_WIN98ORGREATER         0x05
+#define OS_WIN98_GOLD             0x06
+#define OS_WIN2000ORGREATER       0x07
+#define OS_WIN2000PRO             0x08
+#define OS_WIN2000SERVER          0x09
+#define OS_WIN2000ADVSERVER       0x0A
+#define OS_WIN2000DATACENTER      0x0B
+#define OS_WIN2000TERMINAL        0x0C
+#define OS_EMBEDDED               0x0D
+#define OS_TERMINALCLIENT         0x0E
+#define OS_TERMINALREMOTEADMIN    0x0F
+#define OS_WIN95_GOLD             0x10
+#define OS_MEORGREATER            0x11
+#define OS_XPORGREATER            0x12
+#define OS_HOME                   0x13
+#define OS_PROFESSIONAL           0x14
+#define OS_DATACENTER             0x15
+#define OS_ADVSERVER              0x16
+#define OS_SERVER                 0x17
+#define OS_TERMINALSERVER         0x18
+#define OS_PERSONALTERMINALSERVER 0x19
+#define OS_FASTUSERSWITCHING      0x1A
+#define OS_WELCOMELOGONUI         0x1B
+#define OS_DOMAINMEMBER           0x1C
+#define OS_ANYSERVER              0x1D
+#define OS_WOW6432                0x1E
+#define OS_WEBSERVER              0x1F
+#define OS_SMALLBUSINESSSERVER    0x20
+#define OS_TABLETPC               0x21
+#define OS_SERVERADMINUI          0x22
+#define OS_MEDIACENTER            0x23
+#define OS_APPLIANCE              0x24
+
+BOOL WINAPI IsOS(DWORD);
+
 #include <poppack.h> 
 
 #ifdef __cplusplus