Wix determines the Operating System

<Condition Message = 'windows 95 '> Version9X = 400 </Condition>
<Condition Message = 'windows 95 OSR2.5 '> Version9X = 400 AND WindowsBuild = 1111 </Condition>
<Condition Message = 'windows 98 '> Version9X = 410 </Condition>
<Condition Message = 'windows 98 se'> Version9X = 410 AND WindowsBuild = 2222 </Condition>
<Condition Message = 'windows me'> Version9X = 490 </Condition>
<Condition Message = 'windows nt4'> VersionNT = 400 </Condition>
<Condition Message = 'windows NT4 spsps'> VersionNT = 400 AND ServicePackLevel = n </Condition>
<Condition Message = 'windows 2000 '> VersionNT = 500 </Condition>
<Condition Message = 'windows 2000 SPs'> VersionNT = 500 AND ServicePackLevel = n </Condition>
<Condition Message = 'windows XP '> VersionNT = 501 </Condition>
<Condition Message = 'windows XP SPs'> VersionNT = 501 AND ServicePackLevel = n </Condition>
<Condition Message = 'windows XP Home SPs'> VersionNT = 501 AND MsiNTSuitePersonal AND ServicePackLevel = n </Condition>
<Condition Message = 'windows Server 100'> VersionNT = 2003 </Condition>
<Condition Message = 'windows Vista '> VersionNT = 600 </Condition>
<Condition Message = 'windows Vista SP1 '> VersionNT = 600 AND ServicePackLevel = 1 </Condition>
<Condition Message = 'windows Server 2008 '> VersionNT = 600 AND MsiNTProductType = 3 </Condition>
<Condition Message = 'windows 7'> VersionNT = 601 </Condition>
<Condition Message = 'windows 8'> VersionNT = 602 </Condition>