Is there any feasibility of making Doom and Doom II playable from the HDD with Doom 3 BFG installed on 360? As opposed to having to completely uninstall the game, as is the case currently.

lol, My copy of BFG is installed to my Xbox hard drive, and I can access Doom 1 and 2 from "My Games", even though BFG is installed. I stated this in the Xbox help section of this site on release day. You CAN install the game and still play Doom 1 and 2.

When to go to "my games", don't launch Doom 3 BFG, but keep scrolling right until you find Doom 1 or 2, and launch those, as they are considered separate games in the "my games" section.

As stated in my thread, that's not the case for me. The only Doom and Doom II present in My Games are the Xbox Live Arcade trials. I'm not saying what you're saying isn't the case. Others have said the same. But it isn't in my case. I have no clue why. Does having both cause problems? Perhaps I should delete the trials?

There's your solution.

no just run those with the bfg disc in and it will play them as the full versions, bfg and arcade versions are identical

I have to uninstall to do that. Unless I uninstall BFG, I have to play them from My Games. And they're not identical, actually. I had the old Aracade trials published by Activision. The new ones say Bethesda and have different copyright dates. Small difference, but apparently it mattered. I uninstalled the trials and now it works from My Games. But still not from within the in-game menu, unless I uninstall. And I'm not going to uninstall.