Googling “MPASMWIN.exe download” and grabbing it from a random DLL/EXE website is dangerous. These files are often:
Microchip no longer offers MPASM as a standalone installer. The best way to get the latest stable MPASMWINEXE is to install MPLAB X IDE and manually add the legacy toolchain. mpasmwinexe download best
To use MPASMWINEXE from any command prompt: Googling “MPASMWIN