Add example for C2103

Author: Rageking8

docs/error-messages/compiler-errors-1/compiler-error-c2103.md

@@ -1,13 +1,23 @@
 ---
 description: "Learn more about: Compiler Error C2103"
 title: "Compiler Error C2103"
-ms.date: "11/04/2016"
+ms.date: "03/04/2024"
 f1_keywords: ["C2103"]
 helpviewer_keywords: ["C2103"]
-ms.assetid: dfe95972-35e9-469a-b8a8-52c849d4e4e4
 ---
 # Compiler Error C2103
 
 '&' on register variable
 
 You cannot take the address of a register.
+
+The following sample generates C2103:
+
+```c
+// C2103.c
+int main(void)
+{
+    register int x = 1;
+    int* ptr = &x;   // C2103
+}
+```