krypthon

hi, just bought downloaded and installed arma 2 oa. to my surprise when i try to start the game i get a message telling me that no dvd drive was found! when i activate a virtual dvd drive (no emulation) i get a message that the original dvd is not inserted. there is also a link to securom site. also upgrading to 1.05 works but when i want to install the 1.05 to 1.07 patch i get an error message that installation does not exists or is corrupted. i bought from gamersgate thanks for the help