REX v2 installation problem!

[coolness]

About half a year ago i bought Real Environment Extreme v2 for FSX but since then i've got a new PC and now that i have installed FSX on it i also want REX to be installed again. I have succesfully downloaded REX to my PC, but when i install it and it starts to unwrap the files, it keeps telling me this: ERROR: Open In_File Failed!
Maybe this is a common problem, and i have done a lot of research but could not find any solution for it. Please help! Peace out!