Microsoft .Net Framework v4.0 was not not found
You have checked the Add/Remove Programs in Control Panel and .Net framework 4.0 is listed as installed but you sill receive a message when trying to install AMOS that it is not installed.
Resolving the problem
Uninstall .Net framework 4.0 and install it again from the following location:
Once installed from the above link the AMOS installation should proceed without error.