"All of a sudden, I just hit the jackpot," says Louise Chavez.
"I couldn't believe, you know, $42 million?" she tells INSIDE EDITION.
But casino executives claim the slot machine was malfunctioning, and they're refusing to pay her the money.
"This is like a nightmare to me. I was a million dollar person for one second and all of a sudden, boom," Chavez says.
She makes about $12,000 a year as a home health aide. She went to the Fortune Valley Casino in Central City, Colorado to celebrate her 53rd birthday. At 11 p.m. she hit the jackpot! She even wrote down the exact amount she'd won: $42,949,673.84.
"Of course I had dreams of what I was going to do with that money. It was not until about 4:30 in the morning that I was told the machine malfunctioned."
"So for five hours you thought you were multi-millionaire?" asks INSIDE EDITION's Les Trent.
"Oh yes, I did," she says.
The casino is blaming a glitch in the slot machine, saying, "The payout amount in question is under review as it does not exist as a potential payout by that machine, in our casino or in Colorado." Colorado gaming officials are also investigating.
"What I want is the money that was shown on that slot machine that I won," she tells INSIDE EDITION.
In fact the machine itself shows a top prize of only $251,000.