Xbox Live Arcade and HDD

[momobeast]

Just a random question guys.

I have a few Full Xbox live arcade games on my 360. On saturday I took off my HDD and whacked it in my mates 360, to show him GW and have a couple of games of Bankshot.

I loaded up my profile from the HDD just as usual, but could not play the full version of any of the games - only the trial version. Whacked the HDD back in my 360 and hey presto there they all are as usual.

Any ideas? I thought saved games/arcade game were stored on the HDD???

[Myth]

If I remember correctly I thought it says somewhere that the games will only work on the console they're downloaded to.

I might be wrong though, however if true what the hell happens if you get a replacement console?

[Rossco]

Games are attatched to your Live Gamertag, if you logged in as yourself on your mates 360, I believe it would work.