During their seven-year marriage, Fred Astaire often told his wife, Robyn: "People have taken advantage of me all my life. Try to see that it doesn't happen after I'm gone."

That has been Mrs. Astaire's consuming mission since the dancing actor's death a year ago."I didn't realize how difficult it would be," she said. "Everyone wants a piece of Fred now."

She cited a Hollywood Boulevard operator who has been selling life-size cutouts of Astaire to be used in stores and amusement parks. Companies have tried to merchandise Fred Astaire lines of tuxedos, jewelry and cologne. Robyn Astaire has hired a lawyer to try to police such ventures, and she is supported by new laws protecting the names and images of deceased celebrities.

Mrs. Astaire is also disturbed by the use of her husband's name and works by companies or individuals who don't consult her, such as the sale by MCA to the Disney Channel of the Astaire TV specials, the only films that he owned. He made his classic musicals while under contract to studios.

She doesn't rule out licensing of products that met the Astaire standards of class.

"Fred wanted me to do that," she said. "He was so afraid that he wouldn't be able to provide for me after he was gone. You see, when he turned 78, he decided it was time to put his affairs in order. He never expected to marry again, so he gave most of his wealth to his family, keeping only what he needed to live on."

Then he met Robyn Smith, a lithe, young jockey who had broken the sex barrier in thoroughbred racing. They were married June 24, 1980, when he was 81 and she was 35. The marriage astonished Hollywood and appalled Fred's sister, Adele, and daughter, Ava. But it endured.

Mrs. Astaire recently talked about her life with Fred at the hilltop home she shared with him. It is unchanged, as is she; daily running keeps her 5-foot-7 frame at 106 pounds.

"By the time we were married, Fred had done everything in his life - more than once," she related. "He was in a mood to relax and take it easy. That was fine with me. He was such an exciting person to be around that we didn't have to do a lot. We just always had a lot of fun - I know that.

"I was happy with my life before that. As with any athlete, when you get into your 30s, you are forced to retire. Everyone thinks you're over the hill when you turn 25.

"Besides, Fred wanted me to get out of the (racing) business because it was very dangerous. I was ready to quit anyway. But I made Fred sell his horses because I wasn't about to let him run them if I couldn't ride."

Fred and Robyn Astaire played some golf together and attended the latest movies, "always at 12 o'clock at a neighborhood theater so he wouldn't be recognized." She even had him watch his own movies at home.

"I had never seen a Fred Astaire picture that I can remember," she admitted. "I just wasn't interested in musicals when I was young. I never realized what I had missed.

"Fred never liked watching himself in movies. But I wanted to see them, and they absolutely blew my mind. At my insistence, he started watching them with me. He was so cute. When I said, `Oh, darling, it's so spectacular,' he'd say, `Oh, was it really good?' Toward the end of his life he enjoyed watching the films, which he had never allowed himself to do."

"I Won't Dance" goes the old Astaire tune, and he wouldn't do so after his last TV show at 70. But on their rare appearances at Hollywood events, Fred danced with Robyn. And nightly after dinner, they exited the dining room in a comic tango that convulsed the servants.

Astaire was in perfect health until the last six months of his life, she said. He started losing weight, and that alarmed her. His doctors could find nothing wrong, but Robyn feared that he might develop pneumonia, the killer of the aged.

"I thought Fred would live into his 90s," she said. "His mother had died at 96, and he was just like his mother. All of a sudden when he reached 86 he started to get weaker and weaker. He wasn't ill; his batteries were draining."

Last June, he developed pneumonia. She drove him to Century City Hospital late at night to avoid public notice, and entered him under his mother's maiden name. His presence there was kept secret until his death on June 22.

For the past year, Mrs. Astaire has devoted herself to preserving her husband's rich legacy, but she realizes she will need to start a life of her own. Next month she is enrolling in an intensive course at the University of California at Los Angeles to determine what kind of a career she should pursue.

She grinned: "I just hope the results don't show that the only thing I'm qualified for is to be a jockey."