The recently released Office 2010 beta provides an option to upgrade your existing version of Office 2007 to Office 2010. You can either chose to upgrade the current version of Office to Office 2010 beta or selecting Customize allows you to set your current version of Microsoft Office to coexist with Office 2010 Beta. To upgrade from the existing version, run the set up file from the Office 2010 installation CD or the exe file.
Accept the terms of the license agreement and click continue.
In the next step you will have two options, one to upgrade the current version or to customize the install. If you select Upgrade from this option, then your older version of Office will be replaced with the new Office 2010 beta.
Selecting Customize allows you to set your current version of Microsoft Office to coexist with Office 2010 Beta, with the exception of Outlook and SharePoint Workspace (formerly known as Microsoft Office Groove 2007). Outlook 2010 and SharePoint Workspace 2010 cannot coexist with previous versions on your computer, so you will need to select one version of the program to have installed on your computer.
Since Outlook 2010 cannot exist with previous version, you can have only one version. So if you do not want to upgrade to Outlook 2010, then unselect this from the installation options tab. Once you have selected the version click upgrade. You can also selectively upgrade using the third option available in the customize window.
Now Office 2010 will install on your machine with the option selected by you. Office 2010 Beta software will no longer function after October 31, 2010, If you had selected Upgrade to Office 2010 Beta directly instead of Customize to set the Beta to co-exist with your original Microsoft Office version during the download process, you will need to manually reinstall your previous version of Microsoft Office to resume your original setup.