Windows Vista Ultimate combines all the features of the Home Premium and Enterprise editions, plus "Ultimate Extras". 64-bit Ultimate supports 128 GB of RAM.
Microsoft released two notable variant versions of Windows Vista Ultimate: Windows Vista Ultimate Upgrade Limited Numbered Signature Edition, and Windows Vista Red. The Signature Edition featured Bill Gates' signature on the front of the packaging along with a unique number; the edition was limited to 25,000 copies. Windows Vista Red was a version released to raise awareness of AIDS in Africa. This edition was available pre-installed on select Dell computers and also through The Ultimate Steal.
|Component of PC||Vista Capable||Vista Premium Ready|
|Processor||800 MHz||1 GHz|
|Memory||512 MB||1 GB|
|Graphics card||DirectX 9.0 capable||DirectX 9.0 capable and WDDM 1.0 driver support|
|Graphics memory||64 MB||128 MB|
|HDD capacity||40 GB||80 GB|
|HDD free space||15 GB|
|Optical drives||DVD-ROM drive (Only to install from DVD-ROM media)|
Physical memory limits
Maximum amount of RAM that Windows Vista can support varies, depending on the both its edition and its processor architecture, as shown in the table.
|x86 (32-bit)||x64 (64-bit)|
|Ultimate||4 GB||128 GB|
|Home Premium||16 GB|
|Home Basic||8 GB|