Hey there, sorry to hear about your trouble. In the local game folder for the game (you can get to that from Properties in the steam window), you might try going into the RuntimeData subfolder and renaming or deleting your settings.dat file and settings.bak file. That will make you enter your profile name again and so forth, but it will let you on.
Alternatively, if you open up settings.dat in a text editor of your choice, you can find the line where it says something like AutomaticallyCheckForUpdates:1 or something along those lines. Change the 1 to a 0, and that might solve the problem.
Lastly, if you set the game to predownload all of the images (it's a setting in the settings menu, then that's probably the issue on a 2GB ram machine. It's probably trying to preload way too much and then flipping out the OS a bit. I'd only use that setting on a machine with probably 4GB of ram. Not using that setting won't hinder your gameplay at all.
Hope that helps!
