There's a few guides around the web that say how to limit Win7 or Win8 to 2GB RAM, in order to get Motocross Madness 2 to work correctly.

But all you need is Microsoft Application Compatibility Toolkit, then make a new fix against mcm.exe in the game install folder, click next until you get to the Compatibility Fixes, then tick GlobalMemoryStatus2GB. Complete that then click File > Install (you might have to save your collection of game fixes first (rename it to something you like!) then it'll be installed and no need to run ACT again.

However: I have to use WinXP compatibility mode as well (at least) or it only starts in Software mode. In hardware mode only 640x480 resolution can be selected (this in on Win8.1 with Nvidia 980).

In software mode, higher resolutions may be selected, but only the ones directly below the 640x480 selected (as the resolutions may repeat 4 times), so scroll carefully. Selecting one outside that list will cause the game to crash.