Hi, the location is \users\[yourname]\appdata\local\Frontier developments\...
Note the space there. I have one called Frontier_developments (with underscore) too, for some reason... that's NOT it.
In there you'll have options\bindings
But there are a bunch of other things as well, I would save the whole "Frontier Developments" directory, just in case. Then after reinstall, try to cherrypick if I find something that doesn't work.
Although this whole thing is separate from the install directory, so I would expect it to stick around after an uninstall, so you don't have to do anything. But hey, haven't tried it yet, so better safe than sorry.