Thanks a lot, TryNinja! It worked perfectly. I sort of guessed this should work, but had an information overload in my brain.

Hi!

Half a year ago I bought bitcoins and sold them immediately just a few weeks later. This week I bought bitcoins again. I used Electrum again and send 1 of the bitcoin addresses to the seller. Then I waited Electrum to synchronise. And it kept synchronising for days, because I read it could take quite some time. It turns out I'm using an obsolete version of Electrum (2.5.4) So I installed the latest version of Electrum. It is installed in a different folder. When it asks for a wallet I point it to my old wallet, but it doesn't recognise the file format. And this is where I am right now. I am not sure what to do. Can I just create a new wallet with my seed (still got it) and will it generate the same addresses etc? So, when I do this I probably will see the bitcoins on the address I gave out? (Maybe this is a basic issue and it seems very simple, but I'm quite lost right now.)

Thanks for any help!