I recently installed the FDM Workbench client and at around 75% of the installer I encountered two errors:
One warning to say system files were being overwritten and I would need to insert the installation disk.
One error saying MDAC 2.8 cannot be installed on this operating system:
If I clicked the X on the MDAC error the whole PC restarted itself.
The solution is to run the installer again and when the errors appear this time just leave the error boxes open.
Wait a little while until the installer reaches around 83%. Then kill the process "msiexec".
The installer will complete successfully.
The installation file that failed is "C:\Oracle\Middleware\EPMSystem11R1\products\FinancialDataQuality\SharedComponents\MergeModules\HyperionFDMMergeModules.msi".
You can just manually run this file to ensure the installation is complete!