Не е точно Windows ALL, защото е базирана на .NET 2.0, ето неговите изисквания:
System Requirements
Supported Operating Systems: Windows 2000 Service Pack 3; Windows 98; Windows 98 Second Edition; Windows ME; Windows Server 2003; Windows Vista Business; Windows Vista Business 64-bit edition; Windows Vista Enterprise; Windows Vista Enterprise 64-bit edition; Windows Vista Home Basic; Windows Vista Home Basic 64-bit edition; Windows Vista Home Premium; Windows Vista Home Premium 64-bit edition; Windows Vista Starter; Windows Vista Ultimate; Windows Vista Ultimate 64-bit edition; Windows XP Service Pack 2
Ако се вгледате внимателно, ще видите, че има и неподдържани версии, 95 например, да не говорим и за 3.х :)