Hi
I see you have 8 cores CPU, is it with HT enabled? I remember some people ran into problems with the game with more than 4 cores available or with HT technology enabled. I would suggest the following:
1) Set game process affinity to 1 or 2 cores in the task manager. To do this run the game, in main menu press Ctrl+Alt+Del, invoke the task manager, find game processess (Kursk1943.bin and Kursk1943.exe or Africa1943.bin and Africa1943.exe since you said you have ToW2), right-click on each and set affinity to cores 0 and 1 or only core 1 (uncheck other cores). Then Alt-Tab back to game and try to load a mission again.
If you bought the game on Steam, you can do this easier (
read here).
2) If this doesn't help, temporarily turn off HyperThreading in BIOS to see if this helps.