Does anyone know what is the requirement of Windows Vista?

Microsoft has set two different sets of Windows Vista requirements, Capable PC requirements and Premium Ready PC standards. The Capable PC requirements detail the minimum standards a computer must meet in order to run the "core" Vista features. In order to run Vista, a computer must meet the following standards: -800 MHz 32-bit (x86) or 64-bit (x64) processor -512 MB of memory -SVGA graphics card with 800x600 resolution or higher -20 GB hard drive with at least 15 GB free -CD-ROM drive If you find the requirements confusing, simply look for a "Designed for Windows XP" or "Windows Vista Capable" sticker on a new PC. If your computer doesn't have a sticker and you want to know how well it will run Vista, try Microsoft's Vista upgrade advisor. Although Capable PCs meet the requirements to run Vista, they can't run all features, including Windows Aero. In order to run every feature available in Vista, a computer must meet the Vista Premium Ready requirements: -1 GHz 32-bit (x86) or 64-bit (x64) processor -1 GB of memory -Graphics card that is DirectX 9 compatible with a WDDM driver, 128 MB of graphics memory or more, Pixel Shader 2.0 technology, and colors defined with 32 bits per pixel or more -40 GB of hard drive capacity with 15 GB free space -DVD-ROM drive -Capability for audio output -Capability for Internet access

At least 1GB of ram will do. Actually it may install in 512MB but it would be very slow esp for Vista Ultimate. If you are running windows XP, most probably your device can run the vista but add more RAM and increase your video graphics accelerator as graphics resolution of vista is very high... I have installed vista ultimate on my sisters laptop with the ffg specs: centrino 1.8Ghz, 512 RAM, 80GB HD (Fujitsu siemens), it's running ok until she give up and told me put it back to XP because she got confused with the new look. Also, there;'s a lot of programs available but not compaitible yet with vista that's why I'm thinking of downgrading my laptop to XP as i bought it with vista home basic installed on it...