A Reno, Nevada branch of software giant Microsoft Corp received a suspicious letter filled with pornography that passed one test for anthrax but failed another and now awaits a final test on Saturday, company officials said on Friday. A Microsoft spokesman said Nevada officials informed the company on Friday night that the second test for anthrax had proved negative after the first one was ``presumptively positive.'' Nevada Gov. Kenny Guinn said earlier in the day that more tests were needed before it could be determined if the letter contained anthrax, a bacteria that has a potential for use in germ warfare. The letter was sent to the Reno office of Microsoft Licensing, a unit of the Redmond, Washington-based software firm, apparently from Malaysia, a spokesman for Guinn said. ``It was return mail from Malaysia containing a check, a bill and the porn. The check and bill were all right but the porn material tested positive for anthrax in the first test,'' said spokesman Greg Bortolin, ``We are taking the situation seriously and working closely with appropriate law enforcement and health officials,'' said Microsoft spokesman Jim Desler. Guinn, in an interview on CNN, said the letter was received by an employee, considered suspicious and given to a supervisor, who contacted authorities. ``I haven't seen it, but my understanding is that it was some pornographic material,'' Guinn told CNN.