Heads up - if you are using Internet Explorer 8 on your system to use Google Apps, I have bad news for you. Today Google has announced that it will be cutting support for Internet Explorer 8 starting November 15th for its Google Apps service.
Now this is not saying that they are completely ditching you, this means that they will stop supporting it. Many services will continue to work as expected, but should you run into an issue, you are going to be on your own.
Now if you are using Internet Explorer on Windows XP, you can fix this by installing an alternative browser, such as Google Chrome, Mozilla Firefox, Opera, and so on. You can click the links to visit the browser's website, and from there you can decide what browser to install. Personally, I recommend Google Chrome, but Firefox is also up there.
If you are using Vista or 7, you can install an alternative browser, or you can upgrade your machine to the latest version of Internet Explorer, in this case IE9 as of the time this article is posted.
If this effects you, I advise you look over the tips above. If you have questions, let me know in the comments.