In a 3-quart saucepan cook bacon over low heat 8 to 10 minutes, stirring frequently, until crisp and golden.
Remove bacon from saucepan and drain excess drippings from the saucepan, reserving 1 tbsp.
Cook onion and garlic in bacon fat over medium heat about 3 minutes, stirring frequently, unitl onions become opaque. Stir in spaghetti, chicken, cheese and whipping cream. Cook, stirring occasionally, until heated through.