Run lazarus.exe again. When the "FPC sources not found" message appears, use the browse button and navigate to the folder fpc/3.2.0/source of your installation directory. If this folder exists everything should be fine. Click OK, and Lazarus should contine correctly.
It is not clear to me why you installation is broken. I just did a test installation and it was working fine, I do not see the "FPC Sources not found" error. A few details on how I did the installation:
- Secondary installation
- installed into c:\lazarus (installation into c:\program files is not recommended because it requires admin rights to install components),
- config directory c:\lazarus\cfg.
- did not register file extensions
I cannot imagine that other settings can produce this error, except for maybe access right issues to the config dir. But please specify how you did the installation.