Suggest upgrading to SP3 or later for invalid certificate errors.

chrome/app/chromium_strings.grd

Index: chrome/app/chromium_strings.grd
diff --git a/chrome/app/chromium_strings.grd b/chrome/app/chromium_strings.grd
index 70ce6c1fd1029f5bdc0e3891e6b20b7d146bdffe..5704c05ee8331a77996327d7fb96c9e1e94205f3 100644
--- a/chrome/app/chromium_strings.grd
+++ b/chrome/app/chromium_strings.grd
@@ -1268,6 +1268,9 @@ Signing in anyway will merge Chromium information like bookmarks, history, and o
           Chromium can't establish a private connection to &lt;strong&gt;<ph name="DOMAIN">$1<ex>paypal.com</ex></ph>&lt;/strong&gt;. This is probably because your computer's date is set incorrectly (<ph name="DATE">$2<ex>Jan 1, 1970</ex></ph>). You should refresh this page after <ph name="BEGIN_LINK">&lt;a href="#" id="clock-link"&gt;</ph>you update your computer's date and time<ph name="END_LINK">&lt;/a&gt;</ph>.
         </message>
       </if>
+      <message name="IDS_SSL_NONOVERRIDABLE_MORE_INVALID_SP3" desc="Body text for the explanation shown if the user clicks on the details windows, the certificate is invalid and the user has an old version of Windows (before WINDOWS XP SP3) running.">
+      Your computer is running an old version of Microsoft Windows that cannot process this website's security certificate. Because of this problem, Chromium can't tell whether the certificate came from <ph name="SITE">$1<ex>google.com</ex></ph> or from someone on your network pretending to be <ph name="SITE">$1<ex>google.com</ex></ph>. Please update your computer to a more recent version of Windows.
+      </message>
 
       <!-- OOBE -->
       <if expr="chromeos">