This is the most common email we get asking how to deal with finding the files when your computer has crashed.
To start with make sure you do a backup. I recommend using an online backup service. I use and love Backblaze. They have fantastic support and their fee covers external drives (many do not). SO I always start by reminding everyone to back up your website files, just as you should your regular files.
If you have had a computer crash you can find the steps to reload your website here.