I just installed The Last Express and tried to run it, but as soon as dosbox entered fullscreen it crashed. When I take the fullscreen setting out of the config, it launches and works fine, but as soon as I press alt+enter to go into fullscreen, it crashes again. The dosbox window just goes black and then closes. Anyone got any advice? I'm on windows 7 64 bit.

Try setting a different graphic mode with the "Graphic mode setup" tool. At least one of them should work.

You can find it in the start menu (usually Start -> All Programs -> GOG.com -> The Last Express -> Graphic mode setup).

The fact that fullscreen does not work in the standard setting could point to a problem with your graphics drivers, so I recommend updating them as well.

Thanks for your response. I tried all of those output settings, unfortunately none worked. I also noticed they weren't actually changing the output setting in dosboxTLE.conf, so I tried changing manually between them all in there, still no dice. I'll try updating my drivers later, but I don't hold out much hope... I do have a recent driver and everything else works fine in it (including using dosbox with another old adventure game, Callahan's Crosstime Saloon), what are the chances that it needs the most recent driver update to fix dosbox and an ancient game?

You are right, that does not make sense.

Try this: Since DOSBOX uses SDL there should be two log files called "stderr.txt" and "stdout.txt" in the folder where the game is installed (also look in the DOSBOX subfolder, there could be a second copy of those files). These are usually deleted when the program terminates normally, but will remain there if the program exits in an unexpected way. If we are lucky they will contain an error message that can help us further.

If the files are not there or empty, try opening them both while the game runs in a window and again after the crash on switching to fullscreen with Alt+Enter (remember to check both the main program directory as well as the DOSBOX subfolder). I hope to see something like "bla bla failed to initialize".

Edit: Are you running Windows Vista or 7? The fact that dosboxTLE.conf was not updated by the GOG tool points to a problem with write permissions of the game folder. This would also prevent these files from being created. If so, try changing the write permissions of the folder and the DOSBOX subfolder.

I'm running on windows 7, but I'm an administrator with UAC turned off. Good tip on the stdout files, I got this from stdout.txt:

"DOSBox version 0.74
Copyright 2002-2010 DOSBox Team, published under GNU GPL.
---
SDL_Init: Starting up with SDL windib video driver.
Try to update your video card and directx drivers!
CONFIG:Loading primary settings from config file dosboxTLE.conf
Memory sizes above 31 MB are NOT recommended.
Stick with the default values unless you are absolutely certain.
MIDI:Opened device:win32
Exit to error: Could not set fullscreen video mode 640x480-15: Couldn't create DIB section"

I couldn't find any help online about that error, but it does mention updating the drivers (not sure if that's a general message or something related to my problem). I'm just downloading the latest geforce driver now so I'll report back if that helps.

Ok, the driver update didn't fix it, but I did find the problem - I used the DirectX SDK control panel to disable directdraw hardware acceleration some time ago as an obscure fix for a problem in Planescape Torment. Enabling hardware acceleration again there lets me run The Last Express in fullscreen. Hooray!