For installing or reinstalling a Microsoft Office suite and working on Microsoft Excel a Microsoft Excel Product Key is required. It confirms the usage of the software for the user for a limited period. If the Product Key is not correct the user may find difficulties while installing the suite. In case of a trial version of a Microsoft office suite which does not works for a long time the user has to purchase the original product which includes the Microsoft Excel Product Key for the appropriate usage of the software. A trial version of Microsoft Office suite can be converted into a full version Microsoft Office suite by visiting the Microsoft website and purchasing the Microsoft Excel Product Key. The product key is different for a trial version and a full version. If you are using a trial version you can go to the Microsoft website for getting the trial version Microsoft Excel Product Key which validates the software for 60 days. The user may use the full version Microsoft Excel Product Key for lifelong use of the Microsoft Office suite and its application. In case of Microsoft Office 2007 the user can install the suite without the Microsoft product key but for a certain period of time. The applications will open but with a popup which will remind the user about the Microsoft office product key. For example In case of the Microsoft Excel application the Microsoft Excel Product Key will be asked each time the user opens the application. The user is allowed to work on the applications and save the work. After using the software application for 25 times the user will no longer be allowed to use the software until the full version Microsoft product key is purchased. In this case the user is bounded to do more work but can view the saved work. The user must always remember to use the Product Key for the full version if the user is converting trial version Microsoft office suite to full version Microsoft Suite. A full version Microsoft office Suite can be installed in two computers and can be used lifelong of each computer. In case of damaged or for changing the product key the user has to visit the official Microsoft webpage for repairing. In case of the full version Product key is missing the user can contact the Microsoft customer service center for assistance regarding the original product key. Microsoft Customer Support Services Website helps the user regarding any problems they are facing with Microsoft Office suite especially with missing or repairing or damaged products and in purchasing full version Microsoft Office suite with the full version product key.