Europa Barbarorum installer crash

[Junkietomato]

I recently downloaded Europa Barbarorum but the installer of 1.1 messes with my computer. If I click the installer it crashes windows explorer. I thought the problem was with my computer because, after I downloaded EB, it was extremely slow and crashy. I did all I could to fix it without success. I decided to delete the EB 1.1 installer but I couldn't, it was impossible, it either crashed windows explorer or it gave me an error message that the software was being used somewhere else. Thankfully I found a nice piece of software called "Unlocker" which allows you remove any file you can't delete by normal means by just right clicking on the file and selecting the software (I had to right click EB 1.1 installer and wait at least 10 minutes to be able to do this). So, after all this mess, I managed to delete the installer and my computer became normal again. Can anyone explain this? How can just an installer cause so much trouble? I'm using windows 7 by the way.

EDIT: Maybe I wasn't clear enough but I looked all over the internet and haven't found a solution to this problem and I would really like to see if this is some issue with windows 7 because I would really like to play EB. (EB 1.2 installer works well though).