Crash: "Out Of Memory" Error

If you're getting out-of-memory errors on a 64bit Windows variant, please try the "Repair" option in the Patcher. These are pretty much all related to corrupted resources. Also, if you have an ancient install (from the first beta weekend), you should wipe the "RDB" folder and patch up again.

If you're getting out-of-memory errors on a 32bit OS, there's a few things you can do:
* The most effective by far: Upgrade to a 64bit variant. There's little reason not to run 64bit these days; keep in mind that any memory above 4 GB you have installed is completely wasted if you're running a 32bit OS variant. If you're running Windows 7, it's a free upgrade.
* Run DX11 rather than DX9. The DX11 API is far more efficient memory-wise than DX9 on Vista/Win7.
* Run on minimum settings.
* Limit the amount of system bloat you have, in the form of .dlls that get loaded with every process. These fragment the memory address space and increase the odds of an out-of-memory error occuring.
* At your own risk: Apply the /3GB tweak. This can have sideeffects, but usually solves the problems.

I can't recommend specific tutorials or methods, but Googling for "3gb switch" should give you some pointers.