Keystore and updating

I tried my first update on the play store via windows the other day. And it was extremely unsuccessful! I went through the cookbook instructions on here but when I hit use existing key in the apk signer, the game salad creator and keystore window would just close. After a couple of times of doing this, I thought I was doing something wrong and may have overwrote the file where the keystore was (Im fairly confused with this part of the process so I dont know if its somewhere on my computer or not to be honest, I thought i knew where it was as i read about the importance of it but I dont know).

So I contacted both the google play developer support and gamesalad support to see if i was at fault. Neither have helped.
Gamesalad wrote a small message asking what i needed help with and when I explained, that was it nothing back!

Google developer support informed me that I signed up for the keystore reset and offered instructions on how to go about it. But their instructions, I simply cant understand them and the screenshots that are provided dont look like anything ive used before or even seen.

I dont really know what help can be offered on this and I think the easiest path for me is to depublish the app and repubish it as a different listing. Which im ok with as its only got a tiny amount of downloads. However I obviously cant depublish and republish for every update I want to make. So can anyone give any advice on the update process, why does game salad close on me or am I doing something wrong.

Apologies for the length of this post and if its been covered before, I found this process pretty straightforward up until the release and now the update part has me completely stumped!