Windows might require a new os version number. This option allows to modify the build number. The complete default version number is: 5.0.2195 (Windows 2000). The example is 6.1.7601 (Windows 2008 R2). 5 6 Windows might require a new os version number. This option allows to modify the build number. The complete default version number is: 5.0.2195 (Windows 2000). The example is 6.1.7601 (Windows 2008 R2). 0 1 Windows might require a new os version number. This option allows to modify the build number. The complete default version number is: 5.0.2195 (Windows 2000). The example is 6.1.7601 (Windows 2008 R2). 2195 7601