Most Windows installers were created with packagers that do have undocumented command line switches; you just need to trial and error them. I usually use this page to get a list of common switches.
For example, you have an installer for the program "Example" and the installer is "Example_install.exe." The vendor doesn't provide any command line switches and perhaps even gives you an odd look when you ask for them. ;)
Download "example_install.exe" to the C:\temp folder on a test machine and open an administrative command line there.
Type things like:
example_install.exe /a
example_install.exe /q
example_install.exe /s /v"/qb"
example_install.exe /s /a /s /v"/qb"
example_install.exe /sp- /silent /norestart
example_install.exe /s /a /s /sms
example_install.exe /verysilent /norestart
If one of those switches "catches" and starts a silent install, you can use it to create a startup script. (If you're deploying this through AD, you can include a check beforehand to see if it's already installed to prevent it from installing every time the machine boots--even a simple test-path
might do it.)
Shortcut: Some installers (notably java) also extract a bunch of msi files in appdata or some equivalent temporary location. If so, grab those and use those instead of throwing random switches at the wall and seeing if something sticks.
This doesn't always work, but it works more often than you'd think. Good luck!