Structurally, a VB6 application is faultless from the MS Windows perspective and doesn't require any extra activities on behalf of its developer or user to get it up and running on any Windows machine. Neither do the C applications created with the older VC6 Visual Studio that VB6 was bundled with back at the time. In fact, the C2.exe compiler that you can find in the VB6 installation is a somewhat enriched pre-VC6 C++ compiler back end (can't recall now if it was a VC3 or VC4 compiler) that's used to translate the VB6 sources to equivalent C++ and to build "standalone" (in fact, MSVBVM60.DLL-bound) VB6 executables. Since MS' support for all this SW was dropped long ago, it's only natural that neither of them has ever had any associated manifest tool.
To the best of my knowledge, MS has promised to include the MSVBVM60.DLL library (VB6 official runtime) into every future release of Windows at least till the year 2025. The only new feature a VB6 application (or a VC6 application as well, for that matter) may ever need to acquire a "modern" look is a standalone (a.k.a "side-by-side") manifest file that would bind it to a contemporary set of Windows common controls. Microsoft's recommended mantras for application manifests can be found
here.
Since your applications, John, are already bundled to a custom control library (MSCOMCTL.OCX where .OCX = .DLL) that's already equipped with a manifest, they can get by without an own manifest
unless they need to have some system-wide features enabled that aren't specified in MSCOMCTL.OCX' minimalistic manifest. Installers/patchers/setups are an example where such extra manifests would be welcome.
Alternatively, VB6 and VC6 executables may have manifests embedded in their disk files forever as internal resources using 3rd party software such as e.g.
ResHacker.
One more thing to note: while intelligent business AV software like paid Kaspersky, ESET Nod32, Symantec Norton, Microsoft Essentials and a few others would never flag a manifest-less but well behaved VB6 application as potential malware, "free" antiviruses like Avast, AVG, Avira and similar low-end AVs aplenty at VirusTotal.com and similar sites tend to throw
false alarms just on account of such applications having no associated manifest file and/or embedded manifest and/or version info resource.
VB6 has always been, and still is, an awesomely feature rich and most user friendly programming environment; probably the best of the kind even if not the fastest.
