4gb ram
Windows 7 home premium 64-bit can support up to 16GB of RAM
4GB
over 9000
512 gb of ram
The maximum RAM supported by Windows 8 64-bit is 128 GB. This limit is applicable to the standard edition of Windows 8; other editions, such as Windows 8 Pro and Enterprise, also support this maximum. However, the actual amount of RAM you can use may also depend on your motherboard and hardware specifications.
16GB
64 GB
The maximum amount of RAM supported by Vista is 128 Gb (Ultimate, Enterprise and Business).
Approximately 3GB of RAM is the most that Windows XP 32 bit will recognize. ^^^^^^^^^^^^^^^^^^^^^ Right but wrong.... 4Gb of RAM is the maximum amount that can be addressed by a 32 bit operating system
32-bit versions of Windows 2000 support up to 4 GB of RAM minus space used by devices in the address space on non-PAE capable systems. On PAE-capable systems, Windows 2000 can support, depending on the version, up to 64 GB of RAM.
The official minimum for a 64-bit installation is 2 GB of RAM. There is no "recommended" amount, as it depends on what you are trying to do. The maximum supported depends on what edition you are using: Windows 7 Professional and Ultimate support 192 GB of RAM. Windows 7 Home Premium supports 16 GB of RAM. Windows 7 Home Basic supports 8 GB of RAM.
Windows Vista will run on a computer with a minimum of 512 MB of RAM