Have you tried other, similarly demanding games recently?
Try checking your system files (though if only D:OS 2 is freezing, it is less likely a system problem): - click Start, type cmd into the search box, right click Command Prompt and select run as administrator. - type the following command and hit Enter sfc /scannow When that is done, type exit and hit Enter, then reboot your computer. For more details, see: https://support.microsoft.com/en-ca/kb/929833
Try doing a clean boot and then test the game. Click Start, or hit WinKey-R, type in msconfig and hit enter; in the General tab, click Selective Startup, uncheck Load startup items (if required) and leave Load system services and Use original boot configuration options checked. Next, Click on the Services tab, check the box to Hide all Microsoft services, then click the Disable All button, then click OK and reboot the computer. Run msconfig again to switch back to the normal boot configuration.
