The donation, disclosed in a filing with the Federal Election Commission and reported by the Associated Press, comes as the software giant faces suits brought by the U.S. Justice Department and 20 states for allegedly anticompetitive practices. Microsoft has denied any wrongdoing.
"Technology has become a greater and greater part of every day life, and there are more policy issues that affect technology and our ability to innovate on behalf of our customers," said Microsoft spokesman Mark Murray. "What you're seeing is the software industry as a whole, including Microsoft, becoming more active in working to make sure that the industry's voice is heard."
The $100,000 donation comes just weeks after the company's chief executive, Bill Gates, testified before the Senate Judiciary Committee.
FEC records also indicate that Microsoft donated $99,000 in computer equipment to the National Republican Senatorial Committee in March, according to the AP.
All told, Microsoft has donated nearly $400,000 to both the Democratic and Republican Parties during the first four months of 1998, more than it has donated during the previous six years combined, according to the AP.
The FEC filings also showed that Sun Microsystems gave the Republican National Committee $2,000 in April.