Google Chrome 降级方法:
1.控制面板中，卸载Google Chrome;
2.注册表中删除残留信息，可直接执行下面脚本. remove.reg.(直接复制保存为remove.reg，双击运行)
Windows Registry Editor Version 5.00
; WARNING, this file will remove Google Chrome registry entries
; from your Windows Registry. Consider backing up your registry before
; using this file: http://support.microsoft.com/kb/322756
; To run this file, save it as 'remove.reg' on your desktop and double-click it.
[-HKEY_LOCAL_MACHINE\SOFTWARE\Classes\ChromeHTML]
[-HKEY_LOCAL_MACHINE\SOFTWARE\Clients\StartMenuInternet\chrome.exe]
[HKEY_LOCAL_MACHINE\SOFTWARE\RegisteredApplications]
"Chrome"=-
[-HKEY_CURRENT_USER\SOFTWARE\Classes\ChromeHTML]
[-HKEY_CURRENT_USER\SOFTWARE\Clients\StartMenuInternet\chrome.exe]
[HKEY_CURRENT_USER\SOFTWARE\RegisteredApplications]
"Chrome"=-
[-HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\Chrome]
[-HKEY_CURRENT_USER\Software\Google\Update\Clients\{8A69D345-D564-463c-AFF1-A69D9E530F96}]
[-HKEY_CURRENT_USER\Software\Google\Update\ClientState\{8A69D345-D564-463c-AFF1-A69D9E530F96}]
[-HKEY_CURRENT_USER\Software\Google\Update\Clients\{00058422-BABE-4310-9B8B-B8DEB5D0B68A}]
[-HKEY_CURRENT_USER\Software\Google\Update\ClientState\{00058422-BABE-4310-9B8B-B8DEB5D0B68A}]
[-HKEY_LOCAL_MACHINE\SOFTWARE\Google\Update\ClientStateMedium\{8A69D345-D564-463c-AFF1-A69D9E530F96}]
[-HKEY_LOCAL_MACHINE\SOFTWARE\Google\Update\Clients\{8A69D345-D564-463c-AFF1-A69D9E530F96}]
[-HKEY_LOCAL_MACHINE\SOFTWARE\Google\Update\ClientState\{8A69D345-D564-463c-AFF1-A69D9E530F96}]
[-HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Google\Update\Clients\{8A69D345-D564-463c-AFF1-A69D9E530F96}]
3.安装新的版本