Put spaghetti in a large pot of salted boiling water and cook about 8 to 10 minutes, until it is al dente. Drain.
In a large bowl combine the chicken, cooked spaghetti, garlic, capsicum, onion, soup, wine, 1 1/2 cups of the grated cheese, salt and pepper. Mix all together and spread into a 20x30cm baking dish. Bake in the preheated oven for 30 minutes. Top with the remaining 1/2 cup of cheese and bake another 15 minutes.