Hello and thank you, but it is not usefull to continue this discussion. My problem was solved by uing Ccleaner to remove Adobe Reader 7 from my computer. After that, it was possible to install Reader 10 normally.
For your information, I did not identify any process running in the bacground and belonging to to Adobe reader. And if it was the case, usually a restart of the computer sole the problem. I had the problem during several monthes! I suspect it was something wrong in the register, but, using regedit, I did not find it. All informations I found were in english and I am not able to understand "computer english" enough. The on line translators produce usually a french it is not possible to understand too. That's one of the reasons I had the problem during several monthes before to be able to solve it.
