Right, there's a couple of issues I went though.
Are you using Chrome as your web browser to check it?
If so it won't work by default as it's not listed as a supported browser. However if you install the Chrome User Agent switcher
https://chrome.google.com/extensions/detail/aafciojnlamllgpkpdkbamkfgbofhgcjyou can then make chrome temporally pretend to be Internet Explorer which should make garmin connect work.
Alternatively, if you are already using internet explorer, you need to make a couple of security changes.
Click on Tools/Internet Options in IE, click on the security tab, then trusted sites, then the sites button.
Then add
https://buy.garmin.com and
https://connect.garmin.com
Save, restart IE and then try reinstalling garmin connect.
Edited: 08/01/2011 at 20:44