President Reagan thought it was "inappropriate" for White House computers to be simulating the 1984 presidential election, and senior presidential aides have ordered a halt to the practice after one projection showed Reagan would lose to Sen. John Glenn (D-Ohio).

After the computer results were disclosed yesterday, White House spokesman Larry Speakes said, "I think those who are involved know better than to do it again."

The computer projection, a state-by-state electoral vote count in a mythical 1984 contest matching the president first with Glenn and then with former vice president Walter F. Mondale, was prepared by the White House Office of Planning and Evaluation under presidential assistant Richard S. Beal.

The simulation of a 1984 race showed that Glenn could defeat the president but that Reagan would do better against Mondale.

Such projections were used effectively by Reagan's pollster, Richard Wirthlin, to track the 1980 campaign. Beal then worked for Wirthlin.

But Wirthlin said in a telephone interview that he had nothing to do with this simulation, dated Dec. 6. He said it was too early to begin conducting such computer exercises accurately.

Speakes described the simulation as "one of several scenarios going through the computer over there." He said the "worst-case" scenario was the one that was published yesterday.

The spokesman said Beal's office was not told by Reagan personally to stop the computer work, "but they got the message." Speakes said there was no legal objection to the computer work, "but I think it is probably more appropriately done on a computer somewhere else."

"Neither the president nor I nor anyone else believes that scenario" that shows Glenn defeating Reagan, he added.

Speakes said the simulations had not been authorized by any White House senior staff members, but other officials said Beal's work comes under the authority of White House counselor Edwin Meese III.

Also yesterday, the president designated this week as National Drunk and Drugged Driving Week and promised that the federal government would join cities and states to stop "the slaughter on the highways" by drunk drivers.

"Our loved ones are not being killed in drunk driving 'accidents,' and I put the word accidents in quotation marks. They're dying because some of the nation's motorists have turned their vehicles into weapons," Reagan said.

The president's comments came at a ceremony in which he received an interim report from the Presidential Commission on Drunk Driving, formed in April to study a problem that claims 25,000 lives each year.

Included in the commission's specific recommendations is a system by which drunk drivers would pay fines to support local drunk driving programs, and the establishment by states of a 21-year-old minimum drinking age.