Howtogeek posted a guide about adding events to Windows Live Calendar in IE8
Do you have event dates that you need to make note of while browsing in Internet Explorer? Adding those events to your Live Calendar is easy to do with the Add Events to Windows Live Calendar accelerator.Add Events to Windows Live Calendar in IE 8
Adding Events to your Live Calendar
To add the accelerator click on Add to Internet Explorer and then confirm the installation when the secondary window appears.