Put on rubber gloves. Open the dishwasher and sift through the standing water to remove any food, glass, utensils or dishes that may be clogging the drain.
Unscrew the basket covering the drain and remove further debris that may have gone through the filter but built up and clogged the drain. This is most common when there is a large amount of tiny debris.
Pour powdered dishwasher detergent in a bowl with a small amount of water to create a paste. Dip a sponge in the paste and wipe down the interior of the dishwasher to remove hard-water buildup. Hard-water buildup can clog the drain.
Run a normal cycle with detergent after wiping down the interior with the detergent paste used in Step 3.
Pour liquid drain clog remover down your garbage disposal if the dishwasher is still not draining properly. This usually clears out the drain line that connects the sink/garbage disposal to the dishwasher.