4.2.5 Trouble with installation [SOLVED]

The weird part is the demo-version works perfectly, no problems whatsoever. Not sure what could be the difference here.

Okay found the solution:
Avast! Antivirus had to be disabled to be able to run the exe. Odd thing is that there was no info about Avast! doing this. Phew.

: shakefist : @ anti-virus bullshit. I recently switched over to AVG as I let my mcafee subscription run out. Mcafee was fucking annoying. Constantly scanning everything I clicked / opened, which in turn was slowing down how fast my computer was running. I had to disable it each time I wanted to play a game too... well at least it wasn't as annoying as some of the other AV I've tried. I hate it when they pop up notifications every 2 seconds informing you that it's just prevented x attacks or quarantined a potential threat that I don't give a shit about. They should run discreetly in the background.

P.S: I've not tried Avast.

P.P.S: glad to hear you managed to sort it out.