Windows Genuine Advantage no longer required for browser.
Microsoft has allowed users with unverified copies of Windows to access the latest version of Internet Explorer.
The company revealed in an official blog posting that it will no longer require users to have their systems verified through Windows Genuine Advantage in order to use IE7.
Gaining approval from the anti-piracy tool had previously been required in order to use the browser.
Windows Genuine Advantage checks the user's copy of Windows and displays notifications if the software is suspected to be illegal. Microsoft has estimated that up to 20 per cent of all copies of Windows may be pirated.
Steve Reynolds, programme manager for IE7 at Microsoft, claimed that the move was for security reasons.
"Because Microsoft takes its commitment to help protect the entire Windows ecosystem seriously, we are updating the IE7 installation experience to make it available as broadly as possible to all Windows users," he wrote.
Reynolds said that the move is primarily aimed at making all copies of Windows safer.
IE7 contains a number of security fixes and tools to prevent the web-based attacks that plagued IE6. Reynolds claimed that the browser's built in anti-phishing tool, for example, blocks an estimated 900,000 phishing attempts weekly.
Michael Cherry, lead operating systems analyst at Directions On Microsoft, said that Microsoft may have decided that, in this instance, it is worth more to spread IE7 than to thwart piracy.
"Either piracy is a problem or it isn't, and either IE is a part of Windows or it isn't," he said.
"Microsoft appears to be telling us that piracy is significant, and that IE is a part of Windows. So you almost have to conclude that they tolerate piracy when it suits their purpose."