I forgot my Firefox Sync Key the other day when I had to sync a new device. I didn’t even know what it was until this happened (note to self – read things more carefully when you install or sign up for something). If you forget or lost your Sync key or you don’t know where to find it, here are the steps I used to get a new Sync key (which I then saved to my passcard in Roboform).
Go to the Firefox menu. Click Tools > Options > Sync. Click to Setup Sync, then follow these steps to get the new Firefox Sync Key )if you already have an existing Firefox Sync account). Here is my step by step guide with screen shots.
When you generate the new Sync key you should write it down or e-mail it to yourself so you have a copy in the future. Also if you ever get an error after everything is all setup, check out my solution for the unknown Firefox Sync error.