If you really want to clean also the settings, you choose Start -> Run -> Type: regedit and then navigate to HKEY_LOCAL_MACHINE -> Software -> rejetto and delete the key "rejetto".
To delete HFS, you just delete hfs.exe.
Maybe for later versions a setup with uninstall would be useful? I'm not sure what other think about this, maybe there should be a poll :roll:
Anyway If later on if HFS would be distributed with a setup too Setup Generator is a free simple tool I use for making setups:
http://www.gentee.com/setupgen/index.htm