Nvinitx.dll Causes Windows To Run Slowly
A Windows 7 (and possibly others) system will run very, very slowly after login to the point of being unusable. However, it runs normally in Safe Mode.
This may occur if the nVidia library file nvinitx.dll has been added to the AppInit section, which causes it to be loaded for every application.
To remove, boot Windows in Safe Mode and use Sysinternals Autoruns to remove or disable the entry from AppInit.
Then run Windows Update to ensure the system has the latest Microsoft-approved nVidia drivers.