Issue

You are unable to open or start AutoCAD or F/X CAD, and your received the following System Error message:

The program can't start because VCOMP100.DLL is missing from your computer. Try reinstalling the program to fix this problem.

Cause

You appear to be missing the Microsoft Visual C++ Library, which is preventing CAD from starting.

Solution

Download and install the Microsoft Visual C++ Library, linked here.