This download is available to customers running genuine Microsoft Office. Please click the Continue button to begin Office validation. - Don't be surprised if Microsoft pops this message while you were downloading an Excel Invoice Template from Office Online Website.
Office downloads on Microsoft Websites will be blocked for pirated Microsoft Office users - Microsoft has started another WGA like validation program called Office Genuine Advantage to check if people are using genuine Microsoft Office XP and Office 2003 suites. This essentially means that your copy of Microsoft Office will be validated (using ActiveX) before letting you download Office updates from Microsoft download center.
What data is collected ? As part of the OGA validation process, your PC's hardware profile, Windows Product key and the Office Product key will be collected during the validation process.
OGA vs WGA Office validation is separate process from Windows validation. Office validation only validates Office suites and applications, and Windows validation only validates Windows.
How to bypass Office validation ? Though no OGA patch or methods to remove OGA have surfaced on the internet yet, it's again a matter of days before someone releases a hack.
Validate Microsoft Office here | Office Sounds - requires OGA validation
Source: Microsoft Presspass