There is the answer :
I was running with the last official wampserver which seems to be not compatible with php7 (I have made some tests on 4 computers with the same result of my problem).
One of my colleague give me this link: http://forum.wampserver.com/read.php?1,126455 with some tutorials to update wampserver to unofficial new versions. Following this indications I have updated folders wamp/scripts and wamp/lang. After that apache start normally using php 7.
PS : it seems to be some errors with certain php functions. One more fix is to update some other wampserver files, the details are on the link up. But for the moment I haven’t got this errors.
Thank you to all the people who are coming on this page and giving me some help.
I hope in the future some other developers will found answers here.