Now that the Office 2010 RTM is available to download for TechNet and MSDN subscribers, most of the subscribers will certainly move to Office 2010 this weekend. If you would like to upgrade from Office 2007 to Office 2010, you can do it as well.

Please note that Unlike Office 2007, Office 2010 is available both in x64 and x86 versions. You can only upgrade from Office 2007 x86 to Office 2010 x86. If you try to upgrade Office 2007 to Office 2010 x64, you will see the following error message.

So, if you are planning to install 64-bit Office 2010, you need to uninstall your 32-bit Office suite first.

Here is how to upgrade from Office 2007 to Office 2010:

1. Download your Office 2010 setup from TechNet or MSDN.

2. Fire up the installer, enter your product key and click Continue button.

3. In the next screen, accept the license agreement and click Continue to upgrade option.

4. Here you need to click Upgrade button as you would like to upgrade from Office 2007 to Office 2010. Simply click Upgrade button to begin upgrading from Office 2007 to 2010.

5. Once done, you will be asked to reboot your machine. Click Yes for the prompt to reboot your PC and complete the installation process. Enjoy Office 2010!