I could probably post this in the EQ2 forums, but the problem seems to be more hardware/software related than anything.
I'm using XP SP3, and have 3.25GB of Ram.
I used to get "Critical Error: Applicaiton Ran out of Memory when requesting XXXXXXX bytes (limit 2048 MB, current XXMB)" often, but only after a few hours of playing or lots of changing zones. After the latest update I got this error every time the game started. As soon as it started loading the character screen.
I tried a few things, closed down a bunch of background programs, etc. Nothing seemed to work. Searching online I found one forum that posted a solution, supposedly from Microsoft:
http://eq2.elements-guild.eu/forum/viewtopic.php?f=23&t=29
I was a bit hesitant to try it. I'm not exactly sure what it does. I tried to research what the 'switches' at the end did, but wasn't very sucessful.
I ended up trying it, and the game started right up. I'm not sure what exactly it did if anything... maybe it was just a coincidence? Any insight to the problem? I've heard it being caused by me using a 32bit OS, or being caused by me using a 32bit OS with a Nvidia 580 with the latest drivers, or it being a problem with the way EQ2 is programmed. I've had the same issues with Guild Wars 2. Once the program starts to use a lot of memory, the game crashes and tells me I'm out even though the error report says I have plenty of free memory.