Hi Matthew,
Thank you for posting your query on Microsoft Community Forums.
I see that you are getting an error while installing AOE3on windows 8 computer.
I would like you to follow the methods provided to fix the issue:
Method 1: Clean Boot
If you’re able to get on the desktop, then perform clean boot to identify if any 3rd party service is causing this issue:
http://support.microsoft.com/kb/929135
Note: After performing the troubleshooting steps in clean boot, follow Step 3 from the link to start the computer to Normal start up mode.
Method 2: Rename the InstallShield folder
1. In Windows Explorer or in My Computer, open the following folder:
DRIVE \Program Files\Common Files\
2. Right-click the Installshield folder, and then click Rename.
3. Type InstallShield1, and then press ENTER.
4. Try to install the game.
If the problem continues to occur, go to Method 3.
Method 3: Locate and then close the files
To resolve this problem, locate, and then close the Idriver.exe and Msiexec.exe files. To do this, follow these steps:
1. Open the Task Manager. To do this, Press Windows key + CCollapse this imageExpand this
, type task Manager in the Start Search box.
2. On the Processes tab, in the Image Name column, locate idriver.exe and msiexec.exe.
3. Select each instance of both processes, and then click End Process.
4. Click End Process on each Windows Task Manager window that opens.
5. Close the Task Manager.
If you need any further assistance with windows, please reply and we will be happy to help.