Project: System Information Unit.
Unit: PJSysInfo.
Class: TPJOSInfo
Applies to: ~>5.0
class function MajorVersion: Integer;
Returns the major version number of the operating system.
The corresponding minor version number is provided by the MinorVersion method.
When the program is run in compatibility mode, this method will return the major version number of the "emulated" operating system.
On operating systems where CanSpoof returns False
this method will return the major version number of the installed operating system, regardless of any compatibility mode.