I'm using IE6, and if your version is higher, make sure to tick the browser >> tools >>internet options >> advanced >> enable Third-party browser extensions. In addition, if you have 360 or Windows Optimizer master to be in the inside will prohibit plug-in installation, such as cancellation.
Make sure that there are no problems, my Alexa toolbar is still not displayed, view the version of Windows is SP2, from the Internet to check the data, may be the issue of Windows version, you need to re-import the registry files, The registry file here is only for the Alexa toolbar that cannot be displayed, and the following is the content:
Windows Registry Editor Version 5.00[-hkey_local_machinesoftwaremicrosoftinternet Exploreractivex compatibility{ 69A72A8A-84ED-4A75-8CE7-263DBEF3E5D3}]
It's easy to use, save into Notepad, and then change the suffix to 1.reg, double-click the import can be completed, and then restart IE browser when the Alexa toolbar has been enabled. Then click on the browser above the View >> Toolbar >>alexa toolbar tick, and then see the browser above the Alexa toolbar is not already there.