It was bound to happen sooner or later but security firm Symantec is taking legal action against Microsoft accusing it of misusing its technology the BBC reports.
Symantec is angry and alleges that Microsoft improperly used Symantec's data storage techniques in its own software. Symantec wants compensation, saying the alleged infringement amounts to misappropriation of its trade secrets.
The disagreement is based on Symantec's Volume Manager software, which allows operating systems to store and handle large amounts of data.
Symantec believes Microsoft has "deliberately and surreptitiously misappropriated" the technology "and thereby convinced the US government to issue patents to Microsoft based on technologies invented by Symantec".
Symantec is mostly known for its corporate and home anti-virus software that is used widely across the world.
Microsoft describes the accusation as unfounded and says it has tried unsuccessfully to resolve the issue.