This phase II trial studies how well radiation therapy, paclitaxel, and carboplatin work in treating patients with high-risk endometrial cancer. Radiation therapy uses high energy x rays to kill tumor cells. Drugs used in chemotherapy, such as paclitaxel and carboplatin, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing or by stopping them from spreading. Giving radiation therapy with chemotherapy may kill more tumor cells.