If I want to install v1.2 patch the information "Hearts of Iron 2 is not installed on your computer" appears. Of course the game IS installed so the message is quite strange. Any ideas what to do?
Oh, I didn't know that. But does it take any harm by installing 1.2 over 1.1?No. Patches are not cumulative. You can (and preferrably should) apply patch 1.2 directly onto a clean install.