whats the issue with reinstallin?
from what a friend are telling me, it'd be easier to re install. he said this about aram2 but you talking about aram1 hummm
[HKEY_LOCAL_MACHINE\SOFTWARE\Bohemia Interactive Studio\ArmA 2]
"MAIN"="C:\\Bohemia Interactive\\ArmA 2"
cd key needs converted the hexadecimal
in that format,
that's just an example not a actual key in hex
i guess you could try to convert the key to hex, http://en.wikipedia.org/wiki/Hexadecimal
this link might help,
you'll still have to run the patchs i believe, be just as easy to re install, unless you cant find the cd key
but wasnt sure if Arma1 CD key needs converted