Hi, as a player of Arma since 2004, i'm pretty experienced with the game. The computer you have, the touch-smart 600 is unfortunately not good enough to run Arma 2. This isn't the computers fault, but Arma 2 was made on a budget, and has extremely poor optimization. This may seem annoying when you can run better looking game such as Left 4 Dead 2, but this is due to Valve having a lot more time and money to spend making sure the game works/runs better on every Pc. However, there is a possibility I could be wrong, and your computer may be able to run the game. If so, try lowering the brightness and gamma in the video settings. Other than that, I have no idea. Never heard of this or experienced it myself.
If you're looking to get into gaming, you should probably and try and look to upgrade. Whilst your PC was probably quite expensive, this is mainly due to touchscreen and branding. You can pick up a perfectly good computer for just under half the price of your PC (when it was new). If you have a look on Ebay at Vibox, they have some great computers for cheap, and are reliable.