Does this happen when trying to install LTspice?? Or is it already installed, and this happens when trying to run LTspice?
Does it happen after clicking the desktop icon (or Start menu choice) to start LTspice?? Or does it happen after double-clicking on a schematic file to run LTspice and open the schematic?
Or does it happen when doing a simulation (after clicking the running-man icon)?
Or does it happen when LTspice is drawing a waveform plot?