Thanks for the reply, I was hoping you specificly would answer to get the best explanation - which I got 
I understand now. I have another computer that I think has not been in internet in years - meaning, the last time it was online was probably before Bitcoin. I think I'll go with that and see later if reinstall would add some security.
One more question: is there a way to replace the USB-transfer with paper or something like that? Like, print or something the transaction details and then manually add them to the offline machine for signing? I realize this would be quite tedious and I'm definitely not planning on doing it for my small savings, but just wondering in general. That'd be 100% secure against any spyware threat, I suppose.
I understand now. I have another computer that I think has not been in internet in years - meaning, the last time it was online was probably before Bitcoin. I think I'll go with that and see later if reinstall would add some security.
One more question: is there a way to replace the USB-transfer with paper or something like that? Like, print or something the transaction details and then manually add them to the offline machine for signing? I realize this would be quite tedious and I'm definitely not planning on doing it for my small savings, but just wondering in general. That'd be 100% secure against any spyware threat, I suppose.