NEVER double-click the luxecash exe on your own computer - yes it will cause many problems for you.

Luxecash (and many other ppi exe's) are not intended to be installed on your machine, but intended for you to make installs on other peoples machines.
These type of "silent" installers are not very good to promote on websites. They are normally spread by torrents, warez, and sometimes bot-nets.
It is possible to promote ppi on websites but normally this is only done with companies like zangocash, waverevenue, 3xlcash, etc. and usually you must trade something to the user to get them to install the ppi program. These types of installs are normally not silent and therefore they are completely legal but conversion for this type of ppi promotion is usually quite low.