Issue while installing Windows 10 on an early 2011 MacBook Pro I try to install a bootcamp with :

OSX 10.11 El Capitan
Windows 10 Pro (from Dreamspark system, its a license for students)

I have succeeded in installing the Windows 10 .iso file on my USB stick.  I had to edit the plist file of the Boot Camp Assistant (the last version 6.0). I have succeeded in partitioning my SSD in two parts.
Now I boot on the USB stick by pushing ALT when booting. The install process asks me to enter the license key. I precise that the installation process looks like the old one, the Windows 7's one. After the license has been entered, I have an error :

tabtip.exe - Application error
The exception unknown software exception (some hexadecimal) occurred in the program at location (some hexadecimal)
Click on OK to terminate the program

After clicking OK, I can just cancel the installation.
I have tried to copy again Windows 10 on the USB stick. It doesn't change anything.
I have also tried to avoid entering my license key by using the &quot;next&quot; button of the window, but the error occurs just after.
I have tried to install Windows 8.1, it doesn't change anything.
don't try to force boot using EFI if you have MBP early 2011, I have and it succeeded but without sound. the only way to fix the sound problem is to re install it in BIOS boot not EFI