"DLL Hell" refers to the set of problems caused when multiple applications attempt to share a common component like a dynamic link library (DLL) or a Component Object Model (COM) class .DLL Hell is where loading one program breaks another program. Basically, any time an application (or service patch) replaces (or loads) an executable used by another application, there is a risk. It doesn't matter if the executable is an exe, vxd, dll, or something else, the risk is the same, and you, the user, have no control over what is happening.