No, you do not have to pay twice. Just log into the Mac App Store on your MacBook Air using the same Apple ID you used to purchase ARD and go to the Purchases section. You'll be able to download ARD there at no additional charge.
Note, though, that you do not need the ARD app on your iMac. The ARD administration app is installed only on the computer from which you want to work. It doesn't need to be installed on the computer you wish to control; you just set up Remote Management on the iMac. And just FYI, you didn't need ARD just to take control of your home iMac. Screen Sharing is built into every copy of Mac OS X since 10.5.
First of all, thanks for your help.
Yeah, I had been using the screen sharing feature for some time but I guessed that "upgrading" to the remote desktop would make things easier and faster. I guessed wrong.
I followed your directions and yes, now I see ARD right there available for download under the "Purchased" section. However, it says it requires OSX 10.7 and this Macbook Air has 10.6.8. Bummer. The iMac at home runs Mountain lion so it installed with no questions asked.
So I was wrong about several concepts. First, assuming i'd need remote desktop in both computers. Second, by not checking that Snow leopard is not enough in the macbook to run this thing.
Now I guess I'll have to find a solution, since this Air is probably not powerful enough to run Mountain Lion (which I also see right there as purchased and ready to download).
If I cant make this thing work, I'll go back to using just the screen sharing.
You are correct; ARD requires 10.7 Lion. You can find the system requirements for Lion here:
I think all MBA's qualify, but I haven't gone over the specs to be sure. If yours does, you can still order Lion from the online Apple Store if you call them. They'll send you a code to redeem in the Mac App Store.
Whether it's worth it or not is a different matter. ARD and Screen Sharing often are troublesome when used outside of the local network since they depend on ports being open and forwarded and IP addresses not shifting. You might want to look into a different solution such as LogMeIn or TeamViewer. I don't know how they'll compare performancewise with screen sharing and ARD (which use the same technology, VNC, for remote control and hence have virtually identical performance) but they're a lot easier to keep working from remote locations.
Thanks for all the tips!
Since changing operating systems just to allow the use of ARD seems a bit illogical to me (Mountain Lion will probably slow my MacBook Air quite a bit), I guess I'll try to approach the problem using either screen sharing, or one or the other options suggested.
For now, I'll just accept the fact that I paid 60 bucks for installing the ARD program in the wrong computer because the system it uses is not clearly stated in its App Store page. Thanks Apple! Way to go!
Did I talk about system requirements?
No. Read again.
I'll quote myself : "... the system it uses is not clearly stated in its App Store page". Never mentioned system reqs. The meaning was, for example, in which of the machines the software must be installed in and in which it doesn't need to. A bit unspecific in the app page, you must agree. But hey, this is just my opinion.
Sorry, but your statement "because the system it uses is not clearly stated in its App Store page. " seemed to indicate that you believe that the operating system requirements weren't stated. If that's not the case, then I don't know what you mean by "installed ARD on the wrong computer" since you can install ARD on every computer you own assuming it's running 10.7 or later.