Win Vista

Windows Vista Ultimate is the most comprehensive edition of Windows Vista. It is the first operating system that combines all of the advanced infrastructure features of a business-focused operating system, all of the management and efficiency features of a mobility-focused operating system, and all of the digital entertainment features of a consumer-focused operating system.

Windows Vista Minimum Supported System Requirements:
Processor 800 MHz 32-bit (x86) or 64-bit (x64) processor1
System Memory 512 MB
GPU SVGA (800x600)
Graphics Memory -
HDD 20 GB
HDD Free Space 15 GB
Optical Drive CD-ROM drive2
Audio
Internet
1 Processor speed is specified as the nominal operational processor frequency

Win XP Service Pack 3

Though Microsoft still won't confirm that it will release a third
service pack for its Windows XP operating system, a preview version of
the software update has been made available on the Web.
An "unofficial" preview pack of Windows XP Service Pack 3 is available
at The Hotfix, a software download site and discussion forum that
focuses on patches and software updates.
Info Avaiable, but Hidden
Ethan Allen, creator and administrator of The Hotfix, said Wednesday
that he assembled the preview pack from software updates sent by an
internal Microsoft source that are expected to be released in SP3.
The updates include Windows log-on improvements and features that fix
current problems with connecting Windows XP computers to various
networks, according to the SP3 forum on the site.