Min XP Service Pack required is two not one.

chrome/installer/util/install_util.cc

 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // See the corresponding header file for description of the functions in this
 // file.
 
 #include "chrome/installer/util/install_util.h"
 
 #include <shellapi.h>
@@ skipping 60 matching lines @@
   key.Close();
   LOG(INFO) << "Existing Chrome version found " << version_str;
   return installer::Version::GetVersionFromString(version_str);
 }
 
 bool InstallUtil::IsOSSupported() {
   int major, minor;
   win_util::WinVersion version = win_util::GetWinVersion();
   win_util::GetServicePackLevel(&major, &minor);
 
-  // We do not support Win2K or older, or XP without service pack 1.
+  // We do not support Win2K or older, or XP without service pack 2.
   LOG(INFO) << "Windows Version: " << version
             << ", Service Pack: " << major << "." << minor;
   if ((version > win_util::WINVERSION_XP) ||
-      (version == win_util::WINVERSION_XP && major >= 1)) {
+      (version == win_util::WINVERSION_XP && major >= 2)) {
     return true;
   }
   return false;
 }
 
 void InstallUtil::WriteInstallerResult(bool system_install,
                                        installer_util::InstallStatus status,
                                        int string_resource_id,
                                        const std::wstring* const launch_cmd) {
   HKEY root = system_install ? HKEY_LOCAL_MACHINE : HKEY_CURRENT_USER;
@@ skipping 39 matching lines @@
   DCHECK(NULL != registration_list);
   bool success = true;
   for (int i = 0; i < dll_names_count; i++) {
     std::wstring dll_file_path(install_path);
     file_util::AppendToPath(&dll_file_path, dll_names[i]);
     success = registration_list->AddSelfRegWorkItem(dll_file_path,
         do_register) && success;
   }
   return (dll_names_count > 0) && success;
 }