Windows Vista has two main problems which are the following:--
1. Driver problems
Since Windows Vista's launch, the drivers have been a big issue. Lots of hardware components (old and new) had no drivers for Windows Vista or, even if they had, their quality was very poor. One of the most prominent examples is Nvidia. When the GeForce 8800 graphic cards were launched, they were labeled as "Designed for Windows Vista". It is only natural that many people asumed the graphic cards would work well with this operating system. Unfortunately that was not the case, as the Nvidia drivers had lots of issues. There were numerous posts on Nvidia's official forums commeting the bad state of the drivers. Some users even built internet pages such as nvidiaclassaction.info to gather evidence for a class action suit.
Since then, Nvidia worked hard on the Windows Vista drivers and released many new and improved versions. However, their latest driver - Forceware version 158.24 - still has plenty of issues. For example, popular games such as World of Warcraft have low frame rates while others crash during play or have corrupted textures.
Nvidia is not the only company that has these issues. Other big hardware manufacturers such as Creative, renown for their sound cards and sound systems, have similar problems. When Windows Vista was launched, their drivers were mostly in beta stages. Even though they released so called "final versions", their drivers had plenty of issues. Lots of users complained on the official forums and, after a while, Creative announced the ALchemy Project - a project that aims to offer complete DirectSound3D support for Sound Blaster X-Fi products in Windows Vista. Unfortunately, old sound cards such as the Audigy 2 series are not yet supported. Due to lots of users' request, they started the development of ALchemy for Audigy sound cards. However, according to Creative, this products will be offered as a "low-cost" upgrade.
2. Application compatibility
Drivers are not the only problem. Lots of applications do not work either on the new Microsoft operating system. That's because many software developers created applications that function only if the user has full administrative privileges. With the introduction of UAC (User Access Control) and other system changes, lots of old applications have problems. The most prominent example of an application that was incompatible with Windows Vista is iTunes. Whenever the Windows Vista "Safely Remove Hardware" feature was used, it corrupted the user's iPods, requiring a full restore. Also, iTunes text and graphics had display issues with Windows Vista. However, upgrading to iTunes v7.2 or higher solves these issues.