: Do not extract it to C:\Program Files on Windows, as restricted permissions can break the build process. Use a path like C:\Lazarus\ or your home directory instead. Install Free Pascal Compiler (FPC) :
: If you intend to contribute to the Lazarus project itself, you need the source code from the main branch. Lazarus-main.zip
Since you downloaded the (the zip) rather than an installer, you must "make" the IDE. : Do not extract it to C:\Program Files