Wash beets; remove lops.
In 2-quart casserole, place beets and water.
Microwave at HIGH (10) 8 to 12 minutes until tender; stir after 5 minutes.
Drain and cool.
Peel beets and cut into quarters.
Return beets to casserole.
Add sugar, butter and vinegar; cover.
Microwave at HIGH (10) 3 to 5 minutes; stir after 2 minutes.