Unable to activate Arma 1
Please download and install patch 1.14 from here:
http://www.armedassault.com/downloads/ARMAUpdate_1_14.zip
It will remove any online activations. There is a newer patch, 1.18, which you can also use if you have problems with 1.14:
http://www.armaholic.com/page.php?id=8715
Please note that 1.18 can cause graphical glitches on some Win 7 64bit systems.