Oprah Winfrey and Discovery Communications will attempt to goose the ratings on their OWN network with . . . Oprah.

Oprah will host “OWN Your Life: The Oprah Class,” which will become a key part of the struggling network’s lineup. The show will air in prime time — at 8 p.m. — Monday through Friday, starting in October.

“The Oprah Class” will take the nearly 5,000 episodes of the syndicated “Oprah” show and slice and dice them into “classes” — about such Oprahesque subjects as raising children, divorce and forgiveness.

Oprah surprised TV critics, reporters and bloggers at Summer TV Press Tour 2011 when she showed up Friday to introduce Rosie O’Donnell — but really to pitch “The Oprah Class.”

When Oprah and Discovery originally thought of putting the “Oprah” library on the network, it was envisioned as just showing old episodes, under the name “Oprah’s Encore,” Oprah explained.

But one day, Oprah said, she was standing in one of the kitchens of one of her homes, “and thought about This Moment, and realized that this is a dream come true for me — having this platform.”

“Years ago, there was a story in USA Today about The World’s Biggest Classroom,” she said. “It was one of a few articles I’ve saved over the years, and I put it literally on my Vision Board. Because I wanted to embrace the idea of creating The World’s Biggest Classroom.”

And that’s how the idea of “The Oprah Class” was born, to “teach people how to live their best lives” and “magnify and deepen the potential of that library,” she said.

Her friends, Oprah noted, have been telling her since her syndicated show ended in May that they hope she is “enjoying [her] time on the Mediterranean.”

“I’m not. I’m here, in the office, at budget meetings and marketing meetings, and talking about how to strategize and make this network everything it can be to fulfill the potential of the vision.”

This month, Oprah was named chief executive at OWN, replacing Christina Norman, who was shown the door in May because of the network’s low ratings. Then, Oprah named Sheri Salata and Erik Logan — execs at her Harpo company — as co-presidents of OWN.

“The Oprah Class” will be paired with “Rosie,” and both will debut Oct. 10.

Rosie O’Donnell also came to the Press Tour to talk about her new show. Although the network’s aim is “aspirational,” Rosie says her job is to entertain and be funny. Nobody, she speculated, says to themselves: “Oh, if I could only be Rosie O’Donnell: an overweight lesbian who yells too much.”

And like every other Q&A session at Summer TV Press Tour 2011 so far, Rosie fielded absolutely no tough questions, actually thanking the press at the end for neglecting to ask her any questions about Donald Trump or Barbara Walters.