Did it get to the "Loading Browser Plugin" before? If so, try deleting the currentfiles again and try this?
"To anyone having problems getting past the "Loading Browser Plugin" splash page: You MUST leave H&Gsync.exe open and running for around 10-15 minutes. There are 7 files that need to be downloaded/updated and it takes time for the last few files to be completed. Leave H&GSync open and the Heroes & Generals splash page open. Eventually the download packets will come through and the game will reboot automatically. (You will not be able to see the files being downloaded as it is hidden in H&Gsync until completed.)"
Also found:
"try: hngsteamlauncher.exe - run as administrator"
And this:
"Launching from Steam doesnt work, HeroesAndGeneralsDesktop.exe doesnt work, hngsteamlauncher.exe doesnt work. But running hngsync and hng.exe in admin mode..worked!