Frontlines:
For frontlines you need to download and install battlefield 1942 along with all its patches and such. Then you install frontlines. You then copy the folder “desert combat” in the “mod” folder of frontlines, and then paste it into the “mod” folder of battlefield 1942. Then in the mod folder of battlefield 1942, in the desert combat folder that you just pasted, go into the bf1942 folder in the desert combat folder and then into the levels folder. You then need to delete the guadalcanal file. It is very important you delete this as none of the other levels will load and the game will crash when trying to load any levels if you do not delete this file. After this when you launch battlefield 1942, go into the custom games tab and then activate the desert combat game. You have to activate this every time you want to play frontlines.
https://oldpersiangames.org/games/front ... rinenikan/
Break Trough
For the breakthrough it is slightly easier. You need to download and install battlefield 2 along with all its patches and such. Then you install the breakthrough. You then copy the folder isi 15 in the “mod” folder of the breakthrough, and then paste it into the “mod” folder of battlefield 2. After this when you launch battlefield 2, go into the custom games tab and then activate the game. You have to activate this every time you want to play the breakthrough
https://oldpersiangames.org/games/break ... rinenikan/