This shouldn't have anything to do with Windows 8 or 7 or Vista or whatever. The Contact sync should be enabled within the Settings --> Mail, Contacts, Calendar --> "your account". Wihtin this, when I added my Hotmail account I could check if I want to sync only mail or also contacts, calendars and reminders. Did you double check this setting?
Your English is much better than my French so lets carry on as we are if thats ok.
There are two ways to sync contacts with your ipad:
1. iPad settings, mail, switch on the sync for contact, cal's etc
2. within itunes, plug in your ipad and then review the settings for that device. Here you can set itunes to sync your contacts with a specific mail application from that machine. this is typical if your contacts are stored on your pc and you are using Windows Mail that only saves the contacts locally and not on a web based remote server like Microsoft Exchange.
Depending on the mail account you have sometimes dictates the method to use.
I suggest you read the manual and follow its directions:
Sorry, I have been out more than a week. I did check your recommendations, without success. I read the Aplle's manual. I dont find any way to sync Windows Life Mail with iTunes. The guidelines seem to limit the sync with Oultlook 2003, 2007 and 2010 and Outlook Express. However I would like to keep Windows Life Mail. I even try to generated a new mail account under Outlook (W8) without being able to transfer on the PC my contact WLM either in .vcf and in .csv modes, without success. The problem seems then to be limited in the Microsoft's world. I'll try a Microsoft forum.
Therefore I thank you for the assistance,