the right answer, according to other forums as well, is what retrolefty suggested. interlocked relays.
what you guys suggest,which is hardly even a solution, (And i really hope that when you say that the arduino can operate switches, you mean relays), requires tha each window needs 4 relays instead of two.I am searching for the most straightforward solution, not the hardest and most ancient one. imagine if a modern car had to have 16 BEEF relays, JUST for the power windows.
microcontrollers are supposed to make life easier, not create problems...