From Sabily Documentation
What is Wisabi?
Wisabi is a Sabily installer for Windows users that can install and uninstall Sabily as any other Windows application, in a simple and safe way.
It is based on Wubi, the Windows Ubuntu Installer.
Wisabi is available for the 3 versions of Sabily (see differences here):
Wisabi for Sabily 11.04
Wisabi for Sabily 10.10
How do I install Sabily?
Run Wisabi, insert a password for the new account, and click "install". The installation process from this point on is fully automatic. The installation files (approximately 900MB-3.5GB depending on the version (small/full/ultimate)) will be downloaded and checked, after which you will be asked to reboot. Do so and select Sabily at the boot screen. The installation will continue for another 10 to 15 minutes and the machine will reboot again. That's it. Now you can select Sabily at the boot screen and start using it
If you already downloaded a Sabily ISO file, place it in the same folder as Wisabi.exe, so it will be used instead of downloading again the ISO file.
How do I uninstall Wisabi?
Run the uninstaller in "Control Panel > Add or Remove Programs" for Windows XP or lower or "Control Panel > Programs and Features" for Windows Vista or Windows 7. Alternatively, you can run: C:\sabily\uninstall-wubi.exe