1. I did uninstall the Lazarus ( It was installed at D:\#LAZARUS );
2. I did install new Lazarus at D:\LAZARUS;
It is possible that something doesn't like the "#" in your path.
There are known issues with spaces in the path too.
If you uninstall/reinstall lazarus your settings are kept. They are in your user's home folder:
C:\Users\martin\AppData\Local\lazarus
The will contain the old debugger and fpc path (which all can be adapted through Environment / options
If you want a fresh install with complete new settings you can delete the folder.
You can also keep more than one set of settings by using --primary-config-path="C:\foo" (add to commandline, using a windows shortcut)