Go to your Nexon Folder, and create a new Folder. Label it.... Combat Armsz.
now, start up the Installer, but dont press the install button. click ''Browse'' next to where to install it. Find your Combat Armsz folder. and click Install! it should work! Click that little ''Thanks'' button for me, will ya?
i had this same problem and it took me the whole day trying to figure outt..
i tried everything everyone suggested..
reinstalling..all that bs..
solution is to reset ur router..
my router was being retarded and everytime i would start downloading the game it would stop and that error 40 shows up..
okay ive been there... and i escaped the "error 40 hell".... ive been through every single forum and it pissed me off to not be able to get passed stupid error 40...... i found a solution that may be your solution and its not that hard, though it does involve downloading it all over again but it worked on mine and it should work on yours too.
i suggest that you reboot your computer... reset your modem etc just to be on the safe side and make sure it all works out best (incase this shouldnt work for some reason)
so here it is:
1. go into control panel and click on "add or remove programs" and remove combatarms and anything related to it...
2. go into C drive (C:/) and delete the nexon folder and any trace of combat arms stuff.
(make sure theres no trace of combat arms on your computer now..)
3. [Only registered and activated users can see links. ] download this version of combat arms (v.2) takes like 40 mins for my computer... it was like 600mb i think
it should install correctly now... i did these steps exactly and i went from error 40 to correctly downloading combat arms and installing it legit.
4. once it downloads install it (should work.. trust)
5. after it installs.. run combat arms and it should have to install the new patch that was recently uptaded... takes a little while.
IT WORKED FOR ME AND IT SHOULD WORK FOR ALL ERROR 40 PEOPLE..... HAPPY TO HELP YOU ALL OUT AND HOPE IT WORKS FOR EVERYONE WITH THE SAME PROBLEM
btw if you want to add me on c.a my account is leopardftw
my aliceanna account got banned coz my silly friend hacked on it =S