Fully, if you choose the right options.
Using the installer
The upper two checkboxes control how portable Notepad++ is:
- "Don't use %APPDATA%": If checked, the Notepad++ Install Folder is the folder you install Notepad++.exe, typically C:\Program Files\Notepad++\ This option causes Notepad++ not to use the Document and Settings Windows folder. Notepad++ never writes to the registry anyway.
- "Context menu entry": When checked, this causes the installer to register nppcm.dll as a Windows shell extension, for the benefit of an extra "Edit in Notepad++" right click menu entry. If unchecked, no dll will be registered.
Thiese settings completely remove any Notepad++ footprint on the host operating system, so that it can be used on any kind of removable drive without affecting the machine the drive is mounted on.
As a precaution: if your Notepad++ folder doesn't have an empty doLocalConf.xml file, add it. Some versions of the installer are known not to always add the file when portable options are checked.
Using the zipped archive
No installer, no trouble. Add doLocalConf.xml as explained above, if needed.
There is an unofficial U3 version for Notepad++, Please consult http://www.dstrout.net/products/notepad++/ for details.