The judge also said that Johnson didn't have access to IBM trade secrets. "The Court ... believes that IBM has overstated its case. Mr. Johnson does not have the sort of information that is considered quintessential trade secret information--detailed technical know-how, formulae, designs, or procedures," Robinson wrote. In addition, Johnson could suffer great hardship if the court enforced the agreement, the judge wrote.

IBM argued that Johnson could hurt the company because he has knowledge of the "most sensitive confidential strategic information," according to the filing.

Dell declined to comment.