The best, most effective way to cook frozen shrimp is to thaw it before cooking. After the shrimp is thawed, it can be cooked in a variety of different ways.
Cook shrimp in a saucepan filled with boiling water for one to three minutes or until they are pink and no longer translucent. Drain shrimp in a colander, and rinse them with cool water to stop the cooking process. You can also grill, fry or sauté shrimp.
Commercially packaged frozen shrimp goes bad if it is improperly handled during shipment or if it is allowed to thaw and is refrozen. It will also spoil if it is allowed to thaw and remain in temperatures above 40 F for more than 2 hours.
Cooked shrimp is suitable for freezing, but freezing shrimp raw better preserves its flavor. Thaw frozen shrimp in the refrigerator to prevent spoilage, or speed thawing by running it under cold water.
Frozen fish does not need to be thawed before it is cooked. However, cooking fish that has not been thawed does add slightly to the cooking time.
Cooked shrimp can be kept for three to four days in the refrigerator. Fresh shrimp should be cooked within a day or two. Frozen raw shrimp lasts six months, but cooked shrimp should be used within two months of freezing.
According to About.com, cooked shrimp lasts three days in the coldest part of the refrigerator. However, it must be kept in a sealed bag or container to remain consumable.