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 lookups, a thousand for instance of 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 NVTweak \ DisableWindowCaching.

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.