Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Step 1:
Check for any trial version of Office and Uninstall from the computer and then try to install Office Enterprise 2007.
Step 2:
1. Click on Start > All Programs > Accessories > Run > Type %Programdata% and Click OK
2. Rename the 'Microsoft Help' folder as 'Microsoft Help. OLD' and then try installing Office.
Step 3:
Uninstall Office manually and then try to install it again.
Follow the link to uninstall Office.
For 32 bit Operating system:
Follow this link: http://support.microsoft.com/kb/971179
For 64 bit Operating system:
Follow this link: http://support.microsoft.com/kb/928218
Note: Read the registry disclaimer before you uninstall Office.