YEARS BEFORE her outrageous video sexploits, out-of-control rich kid Paris Hilton was enrolled in a high school for troubled kids — only to storm out without graduating, reveals an insider.

Breaking his silence for the first time, the source revealed exclusively to The ENQUIRER that the blonde beauty attended CEDU — a secluded high school in Running Springs, Calif. — in the summer of 1997 when she was only 16.

She acted like royalty from the time she arrived until she made her escape — by limousine — after two months, charges the source, who attended the school with the hotel heiress.

“She was a mess from day one,” the insider told The ENQUIRER. “She was such a spoiled brat that the other rich kids were disgusted with her too!

“Paris was admitted into the school partly to help her to stop her abuse of drugs and alcohol, but all she talked about was finding a way to get out.

“She arrived with several bags of designer luggage like she was going to a resort on vacation. She was more concerned about what she was wearing and what shade of makeup to put on rather than talking about her problems.”

Stuck-up and in love with her reflection, she threw a fit when she learned she could wear only the jeans, T-shirts and sweatshirts supplied by the facility, divulged the insider.

“But that was nothing compared to the tornado she created when they told her ‘absolutely no makeup.’

“Oh, my God! I thought the end of the world was coming the way she reacted to the rules. If Paris wasn’t crying, she was angry — refusing to eat the food or figuring out how to escape.

“Everyone was expected to do assigned chores and to participate in group discussions — but Paris did nothing, except cry like a baby.

“The staff — professionally trained to deal with troubled teens — could not convince this girl to talk about her troubles, and they were very frustrated.”

But the hell-raising Hilton was not without a pleasant side, disclosed the insider.

“As difficult as Paris was, she was just as sweet on a one-on-one basis.

“Paris always used ‘baby talk’ to get her own way. She was very aware of her sensuality — and knew how to use it on men.

“She gave you that gorgeous smile with her head slightly turned to one side. She always moved her legs suggestively — and she tried to kiss me on my neck. For Paris, having attention from men was like breathing — she really needed it to survive!”

The school’s programs — for problem teens of all sorts, not just substance abusers — can run more than two years. But a fed-up Paris called it quits after just two months, the insider told The ENQUIRER.

“Paris outdid herself when she tried to run away. Instead of actually running away — she called for a limousine!

“If it wasn’t so sad, it would have been hysterical.

“Someone — in a limousine — came to pick her up. She immediately dashed for the door and never looked back.

“What’s going on with Paris now doesn’t surprise me one bit.”

Paris, 22, is presently embroiled in a sensational, headline-making scandal over a sexually explicit video.

The tape stars the Hilton beauty giving room service to her former boyfriend Rick Salomon, estranged husband of Shannen Doherty.

Salomon claims the tape was stolen, and footage from the steamy video has hit the Internet — triggering a male meltdown and a flurry of lawsuits.