<Tr> <Th> Old version, no longer supported: Windows Vista </Th> <Td> 0.30% </Td> <Td> 0.54% </Td> </Tr> <Tr> <Th> Older version, yet still supported: Windows 7 </Th> <Td> 41.74% </Td> <Td> 32.67% </Td> </Tr> <Tr> <Th> Old version, no longer supported: Windows 8 </Th> <Td> 1.08% </Td> <Td> 1.84% </Td> </Tr> <Tr> <Th> Older version, yet still supported: Windows 8.1 </Th> <Td> 4.95% </Td> <Td> 6.35% </Td> </Tr>

What is the purpose of windows operating system