Originally Posted by ketchup

The solution that worked for me was the following:

Resetting IE8 to it's default. This means a full reset. Disclaimer: Doing this returns Internet Explorer to its basic state, without any add-ins or other browser extensions. So, if you use IE for your main browser, make sure to remember your add-ins and personal information! You will also "Delete personal settings which removes browsing history, search providers, Accelerators, home pages, and InPrivate Filtering data."

Follow these steps and hope it works, because it's better than not being able to play:

To Reset Internet Explorer Settings Manually -

1. Close any Internet Explorer that are currently open.
2. Open Internet Explorer by clicking the Start button , and then clicking Internet Explorer.
3. Click the Tools button, and then click Internet Options.
4. Click the Advanced tab, and then click Reset.
5. Select the Delete personal settings check box if you would like to remove browsing history, search providers, Accelerators, home pages, and InPrivate Filtering data.
6. In the Reset Internet Explorer Settings dialog box, click Reset.
7. When Internet Explorer finishes applying default settings, click Close, and then click OK.
8. Close Internet Explorer.
Your changes will take effect the next time you open Internet Explorer.

If you are for some unknown reason unable to open up Internet Explorer, you can find the Internet Options with the following:

Go to Start -> Settings -> Control Panel. In the classic view, it will be a regular icon you can open up. In the vista view, You will have to click "Network and Internet" first, then you are able to select "Internet Options".

You can also find an automated version on this website: http://support.microsoft.com/kb/923737

I used the above because of two reasons:

1.) I figured there was something wrong with my IE8 because when I tried to open it, it would freeze on me. It was not letting me click anything at all.
2.) My LoL.Launcher was stuck at the start up screen unable to display server status or the latest news, thus unable to click play.

Now that I did this, the problem is no longer there.