How to make an external USB drive bootable with an older OS ( Win 7)

If the suggestion to install the app on Windows, you may want to try to use a virtual machine instead. You can designate the external drive as the storage for the VHD file, but native installation of Windows 7 is not suported on Intel Processors 7th gen or later or any version of AMD Ryzen, so unless you have an older computer, you are going to have a hard time making it work.

Try to install and run your Literature App on Windows 11 should be an option.
The main challenge is determining if the app is 16-bit or 32.
If the is 16bit applications cannot run natively on 64-bit versions of Windows 11!

However, if the app is 32-bit, there are ways to make it work.

Try Running the App in Compatibility Mode (For 32-bit Apps)

You can try running it in Windows 7 compatibility mode.

Right-click the executable (e.g.,  LiteratureApp.exe or the setup.exe) and select Properties.

•  Go to the Compatibility tab.
•  Check Run this program in compatibility mode for.
•  Choose Windows 7 from the dropdown menu.
•   Click Apply and then OK.

Now, try to run the app and see if it works. Sometimes this is enough to get older 32-bit applications running on newer versions of Windows.

To make your Seagate 232 GB USB drive bootable with Windows 7 and use it to run your literature app.

This process involves installing Windows 7 onto the external USB drive, ensuring that it can boot from it, and running your software as you would on a regular Windows installation, bk your usb, partition it as GPT, making bootalbe , create a windows intaller o  using cd-rom, install win 7, etc.

It's a tedious process that requires skills and hides some pitfalls.
https://rmprepusb.com/tutorials/047-how-to-install-windows-vista-7-svr2k8-onto-a-usb-drive-or-any-partition/

Bye Gastone