If you follow the happenings on the Internet, it has been reported widely that Dell is still giving its customers the option to order their computers with Windows XP installed. At least one of the news articles I read suggested that this was contrary to what Microsoft would want. While there is a lot that can be said in support of an operating system that has been tested with time and has had various bugs and short comings corrected through patches and service packs, Windows Vista remains an unfriendly OS from a usability stand points. There is the ever present UAC which many people have commented about but the manner in which Vista works, relative to Windows XP is a step backwards. While on the subject of UAC, yes I am aware that it can be disabled but I like my system secure and hence I will learn to live with the incessantly annoying UAC.
In Windows XP, unplugging a USB device is user friendly: after successfully unplugging the device, you get a popup from the system tray that informs you that it is safe to remove the device. Otherwise, you get a dialog box which informs you that your attempt to remove the device was not successful. The difference is quite simple: successful removal of the device do not require a mouse click. Windows Vista on the other hand requires a mouse click on both occasions: success or failure. I got tired of clicking on OK during an attempt to unplug three USB devices from a computer.
The other area in which Windows XP wins in the usability department is access to wireless network management related functions. In Windows XP you get to the wireless network right from the system tray; it is even possible to repair a wireless network connection right from the system tray. Windows Vista offer the same conveniences but the wizard that launches after choosing to repair a wireless network connection is just a couple of steps too many. This wizard is just too chatty and complicates what should essentially be a simple process, that takes the minimum number of dialogs possible.
Note: Comparison was between Windows Vista Home Premium and Windows XP Professional (SP2)