Assess the complete runtime
Deployment
16-bit setup launchers, UAC, protected directories and per-user versus machine registration.
Components
OCX/COM architecture, dependencies, licensing and correct 32-bit registry view.
Data and devices
32-bit ODBC/OLE DB providers, mapped paths, printer/serial drivers and obsolete hardware.
Test before changing
- Preserve a working installation and inventory files/registry/DSNs.
- Install in a clean Windows 11 test environment using a reconstructed package.
- Exercise startup, database writes, reports, exports and device workflows.
- Trace failed files/modules rather than applying broad compatibility settings.
- Document rollback and security isolation.
Native, compatibility or isolation?
Native deployment fits when dependencies are supported and reproducible. Compatibility settings can address narrow assumptions but should be documented. A VM or isolated legacy PC is safer when kernel drivers, hardware dongles, unsupported database clients or fragile installers cannot be replaced without operational risk.
Use DLL diagnosis, COM troubleshooting and registration analysis for specific failures. Long-term change belongs in VB6 modernization.
Provide the original installer, working-system inventory, Windows 11 edition/architecture, database providers and connected hardware.