Alexander Ponosov, the principal of a school in a small town in the Ural Mountains region of Perm, was charged with copyright violation last year after he bought a set of computers for his school containing unlicensed Microsoft software.
If convicted, he will have to serve a prison term of up to 5 years and to pay 266,000 rubles ($10,110) in damages.
Ponosov denies any wrongdoing, saying he was unaware the Windows software on the PCs was counterfeit.
Commenting on the case, Microsoft Russia Chairwoman Olga Dergunova said the corporation had not filed any lawsuit against the Russian teacher, reaffirming an earlier statement issued in response to a plea from Mikhail Gorbachev.
The former Soviet leader asked Microsoft Chairman Bill Gates in early February to intervene in the proceedings, which the Nobel Prize laureate described as a "show trial."
Microsoft spokespeople replied by saying it was Russian authorities who initiated the legal action against Ponosov, not the company.
"This case was initiated by Russian authorities under Russian law," Dergunova said.
"In general, we do not believe that a case of this kind warrants criminal prosecution, given the very small number of computers involved and the fact that the computers were purchased for use by students," she said.
Russia, the biggest pirate market after China, has long been facing international pressure to crack down on piracy.
The issue was a major stumbling block in Russia's World Trade Organization accession talks with the United States. The sides eventually signed a final agreement last November after Moscow promised to get tough on intellectual property violations.
However, the Ponosov case has proved quite controversial both at home and abroad, with many observers criticizing the software giant for attacking the small-town schoolteacher as an easy target and accusing Russian prosecutors of using the test case to show off their efforts in combating piracy.
At a recent press conference, President Vladimir Putin called the case meaningless, and said it is the makers and distributors of counterfeit products who should primarily be called to account, not the end users.