Nwiz.exe, commonly referred to nView Wizard, is a component that gets installed when Nvidia video card drivers are installed on a system. It is automatically started with Windows which can be checked with the msconfig command. It is only beneficial on systems that use multiple monitors or tv out settings and can be easily disabled without causing ill or harm to the system even if those settings are used.
This file can cause a high load on Windows systems because it seems to require a Registry key and if it cannot find that key it will constantly bombard the Registry with look ups, a thousand for instance when spawning a new window.
Sounds crazy right? Now the easiest way to check this out would be to install an application like Process Monitor and check if a lot of Registry calls are made that point to NVTweakDisableWindowCaching.
If that is the case you can either create a new DWORD DisableWindowCaching and set it to 0 or disable nwiz.exe from starting with Windows which is probably the best option if your system does not make use of multiple monitors.
Update: Please note that current NVIDIA driver packs don’t ship with nwiz.exe anymore. You can verify that easily by looking at the third-party programs that are set to auto-start with the Windows operating system.
To make sure the file is legit, find out if its location on the hard drive is %ProgramFiles%NVIDIA CorporationnView. If you find it stored elsewhere, especially in directories that have nothing to do with NVIDIA or drivers, then it may be malicious instead.
In later versions, nwiz.exe is also used for loading the nView Desktop Manager which powers features such as zooming or hot key support.