I accidentally fried my Mac OS. My computer has an SSD for the OS and an HDD for data. Does Time Machine back up the OS too? Does it back up both drives? I didn't see an option for that when I set it up. When I restore, it tells me to pick a drive to restore the system. Does that mean the operating system? Should I pick the SSD?
Time Machine backs up you entire Mac, including system files, applications, accounts, preferences, email messages, music, photos, movies, and documents. By default, Time Machine should back up all connected drives except your Time Machine drives. Presumably if it's asking which drive to restore the OS to, you should pick the SSD. I can't verify if it'll attempt to restore the other drive's files there, but I doubt it; at worst, you'll still have your backups and can manually restore from there.