Yeah - we need error message from Steam / Arma ... also there should be an entry in the 'Applications' event logs for when the application crashes.
Please describe the files you tried deleting as well. This shouldn't have to be done as steam basically hashes all your game files and compares them with the hashes on steam servers...so basically if there is even the slightest change in the game files the hash won't match and itll redownload...
Other stuff:
- What anti-virus you use? Why - because some AV has application blacklisting capabilities (most do) and ive seen arma and other games have to be whitelisted to work.
- Have you made ANY changes to you computer since it last worked? Windows/Driver/Application Update, newly installed application, newly removed application, etc etc.
- Does the launcher open and not the game or vice versa
- Did the game work after the tanks update?
- What are your system specs? Answer best you can (Motherboard, RAM, CPU, GPU, PSU Wattage, # of drives)