doc change: Add instruction to disable antivirus before installing SDK components. Add download page link to installing doc.

Bug: 2246467
Change-Id: I15536f3c7f2088fff8f60963ba23a69b1be43804
diff --git a/docs/html/sdk/adding-components.jd b/docs/html/sdk/adding-components.jd
index 967c3521..bc82170 100644
--- a/docs/html/sdk/adding-components.jd
+++ b/docs/html/sdk/adding-components.jd
@@ -54,8 +54,13 @@
 
 <h2 id="InstallingComponents">Installing SDK Components</h2>
 
-<p>Use the Android SDK and AVD Manager to install new SDK components. 
-You can launch the SDK and AVD Manager in one of these ways:</p>
+<p>Use the Android SDK and AVD Manager to install new SDK components. </p>
+
+<p class="caution"><strong>Important:</strong> Before you install SDK components, 
+we recommend that you disable any antivirus programs that may be running on
+your computer.</p>
+
+<p>You can launch the SDK and AVD Manager in one of these ways:</p>
 <ul>
   <li>Execute the {@code android}</a> tool command with no options. If you
 haven't used the tool before, change to the <code>&lt;sdk&gt;/tools</code>