This is not trivial. I want to dual boot my Windows with Debian 11.
To solve the UEFI problem you must boot the installer in UEFI mode. You should see the UEFI information appears in the installer splash screen. If you boot the installer in ordinary/legacy mode, be prepare for the problems. The problem I encountered was unable to install grub.
I boot the installer in UEFI mode from the option from windows, it run smoothly. Magically everything went fine.
Non-free wireless driver must be copied into a drive in a deb file. Plug the drive at the same time as the installer. I've never succeeded this step by hot plugging the drive during installation.
voila.
