# Opening a file - DE Decompiler

> Professional decompiler for VCL applications written in Delphi or built with C++Builder. Analyze Win32/Win64 code, forms, units and classes for reverse engineering, forensics and code recovery.

Canonical HTML: <https://www.de-decompiler.com/help/opening_file.htm>

## Opening a file

Select **File > Open program** to open the binary of a supported Win32 or Win64 VCL application written in Delphi or built with C++Builder.

VCL applications built with C++Builder use the same file-opening workflow. The compiler label distinguishes C++Builder and Free Pascal from Delphi; its tooltip shows full compiler and signature-database details.

1. Choose **File > Open program** and select the input file.

2. Wait for the project tree to populate and initial processing to finish.

3. Check the recovered code structure and forms before proceeding to individual procedures.

### Drag and drop and command-line opening

You can drag a binary from Explorer onto DE Decompiler or pass its path on the command line. Recognition depends on the file contents, so an unfamiliar filename extension or a missing extension does not by itself prevent analysis. Supported Windows shortcuts can be resolved to their referenced files.

Saved analysis databases can also be opened by drag and drop or by passing their path on the command line. Keep paths and file versions unambiguous when working with several builds.

### Cancelling initial analysis

Cancellation is more responsive while opening large applications, discovering classes, reading forms and decompiling all procedures. A pending cancellation stops further procedure processing; cancelling full decompilation still discards its incomplete result.

Cancelling optional prototype analysis keeps the parsed file open and retains the prototypes, APIs and strings already found. Incomplete analysis reports are omitted, and decoding options are restored after interrupted analysis.

### Inputs with limited recognition

The available instructions and metadata determine the detail of recovered names, types and calls. Compiler variation, unusual type information, protection and file damage can affect recognition; inspect an unexpected result in the native instruction view. See [Compiler compatibility and RTTI](https://www.de-decompiler.com/help/compatibility.htm) and [Interpreting recovered code](https://www.de-decompiler.com/help/validation.htm).

For repeatable analysis, preserve the exact binary and record the settings used. A later build with the same filename can have different addresses, layout and behavior.