So, yeah, I just wanted to install Mass Effect 2 through Origin to avoid having to use the disc to start the game.. Didn't go so well..
While downloading it I also decided to install it from the disc, so I could play while I was waiting. I'd then reinstall whenever it finished downloading.
Origin's download speeds are pretty horrible, so I had to have something to do while waiting.
Now, I've set Origin to keep game installers, just in case something goes wrong, which I kinda expected would happen.
While playing, Origin apparently finished downloading and supposedly also finished installing ME2.
Turns out it just saw that the game was already installed and didn't bother installing into the Origin directory.
And launching the game through Origin made it complain about a missing disc..
I had kind of expected that to happen though, which is why I ticked the option to keep installers. But look at that, the installers directory is completely empty.
So, it seems it downloaded the installer, saw it was already installed and then deleted the friggin' installer again

Argh!
So frustrating...