When starting the game after installation, Windows throws and error " D3DX9_41.dll is missing form your computer". I re-installed, no help. I am running Windows 7 64bit.

I am getting the exact same error. Vista 64 on my machine. Have reinstalled to no avail.

EDITED TO ADD: OK, I fixed it by installing the old DirectX package. See point #3 on this page here
http://www.gog.com/en/support/tales_of_monkey_island/ibread_firstb_common_troubleshooting_stepsi