first: right-click the "My Computer" icon
second: click the "HARDWARE",then click "Device Manager"
Yes.
You should install it after Windows successfully boots.
If you have Windows 7 Professional, Enterprise, or Ultimate you can install Windows XP Mode. Or if you want to downgrade you can do a clean install of Windows XP with an installation disk.
If you have the install disc, yes. However it will delete all of your files and settings. It would be like turning on your computer for the first time.
If you are running Windows xp mode on Windows 7 professional, ultimate, or enterprise
Not directly. You can format the hard drive and install Windows XP cleanly. You can upgrade directly to Windows XP Professional (which is more expensive).
Yes.
partition
To successfully install FFmpeg on Windows, you can download the latest version from the official FFmpeg website, extract the files from the downloaded zip folder, and add the FFmpeg bin directory to your system's PATH environment variable. This will allow you to access FFmpeg from the command line.
over 9000
Ultimate is a larger edition than Professional. If you want to downgrade you will need to buy Professional and do a clean install.
It does install, it might nor work properly. Try installing the program in the compatibility mode (windows xp or vista).