Casual
you can avoid this dialog, by find out which product is and deleting the sub key called SourceList
ref
HKEY_CLASSES_ROOT\Installer\Products
revised
looks that if the you delete this key
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office
stop asking for diskette and the app is not working properly
- possible solution for other applications.

you can avoid this dialog, by find out which product is and deleting the sub key called SourceList

ref
HKEY_CLASSES_ROOT\Installer\Products
revised
looks that if the you delete this key
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office
stop asking for diskette and the app is not working properly