Weinstein arrived at the courthouse Thursday morning, and got the bad news shortly thereafter. Once in court, the judge called prosecutors and Weinstein's attorney to the bench ... and said he was not dismissing the indictment.

The attorneys argued at the bench for about 10 minutes -- the media wasn't privy to their discussion -- but at the end the judge stated pretrial will begin on March 7.

The judge issued a written ruling addressing the defense's motion to dismiss -- saying the prosecution is not required to give the Grand Jury evidence that is favorable to the defense.

Translation: There's nothing shady about the Grand Jury not hearing evidence about relationships Weinstein might have had with his accusers. The judge also said the defense's argument the D.A. filed the charges due to "political pressure" was speculative.

Weinstein's legal team had fired off a letter earlier this month informing the judge ... they've found an email claiming to show one of the women alleging he raped her sure didn't act like it, because she went to HIS movie screening only hours after the alleged rape.

The movie mogul's defense has also pointed to a new female witness -- a close friend of one of Weinstein's accusers -- using her to paint a picture of a consensual relationship between Weinstein and his accuser.

Weinstein was greeted in court by several actresses, including Marisa Tomei, Jennifer Esposito, Nia Vardalos and Amber Tamblyn -- who were wearing Time's Up tees.

As we've reported, Weinstein's lawyers filed the motions to dismiss last month. His team also believed the whole case had been tainted ... because prosecutors admitted the lead detective, Nicholas DiGaudio, allegedly hid information about the witness in dealing with prosecutors and allegedly coaxed the witness into not disclosing what she knew.

Weinstein's attorney, Ben Brafman, tells TMZ ... "We are obviously disappointed, by the Court's decision to deny our motion to dismiss the Indictment. Judge Burke has however, ruled and we must accept his ruling. Nothing in the Court's ruling however, removes the flawed theory of this case that we intend to vigorously defend at trial, where we are confident that Mr Weinstein will be completely exonerated."

You'll recall ... Weinstein very publicly turned himself into the NYPD in May and walked out in cuffs on the way to court, where he was charged with rape, a criminal sex act, sex abuse and sexual misconduct for incidents involving 2 separate women. A few days later, Weinstein was indicted by a grand jury on multiple rape charges.

As we reported ... Weinstein was slapped with 3 new sexual assault charges in July for an alleged sexual assault of a woman in 2006. A grand jury charged Weinstein with a first-degree criminal sexual act and 2 counts of predatory sexual assault, which are felonies carrying a maximum sentence of life in prison.

Weinstein previously scored a huge victory when a judge dismissed one sexual assault count from the case involving actress Lucia Evans.