I am trying to sync two PCs. I have successfully used FF Sync on two previous computers. I am now using 2 other computers, with FF 36.0.4 on both. I believe I have not used Sync on one of these computers before, but I think I've used it on the other one. (I'm talking about the "new" Sync.) However, it's possible that I haven't used Sync on either of these computers in the past--that is, I have an existing Sync account but it is not associated with either of the computers I'm trying to sync. I've tried to follow the instructions, but they don't help me at all. When I click on the menu button, I do not see "Sign into Sync" as the Mozilla help page illustrates; instead, I see my email address. When I click on Options > Sync, I do not see "unlink this device" anywhere (see screenshot). This is true of both computers. I don't know what to do.