Windows 8 64 bit Enterprise,Prof essional : 512 GB Windows 8 64 bit :128 GB Windows 8 32 bit : 4 GB Windows 7 64 bit Ultimate, Enterprise & Professional :192 GB Windows 7 64 bit Home Premium:16 GB Windows 7 64 bit Home Basic : 8 GB Windows 7 32 bit (all editions except Starter) :4 GB Windows 7 32 bit Starter : 2 GB Windows Vista 64 bit Ultimate, Enterprise & Business: 128 GB Windows Vista 64 bit Home Premium :16GB Windows Vista 64 bit Home Basic : 8GB Windows Vista 32 bit (all editions except Starter) : 4 GB Windows 7 32 bit Starter :1 GB Windows XP 64 bit : 128 GB Windows XP 32 bit : 4 GB Mac OS X 64 bit :96 GB Linux 64 bit :1 TB Linux 32 bit :4 GB Linux 32 bit (with PAE) :64 GB