Trouble Flashing Redmi 3 With Miflash, Stuck On "send Hello Response"

Apr 26, 2016

so I've just got my Redmi 3 and wanted to install Xiaomi.eu_Redmi3_V7.1.3.0.LHPCNCK_5.1 on a blocked bootloader (just asked for the unlock today, so I'll have to wait 2 weeks).

I have Windows 7 @ 64-bit

I installed MiFlash 2015.10.28.0 with all the drivers.

My phone boots normally to the ROM I've had with the phone when I received it.

Once phone turned on, device manager shows:
Android Phone->Xiaomi Composite MDB Interface
Mobile devices->Redmi 3

Once phone in the Download mode, device manager shows:
Ports(COM & LPT)->Qualcomm HS-USB QDLoader 9008

I start MiFlash, browse the folder Xiaomi.eu_Redmi3_V7.1.3.0.LHPCNCK_5.1 that is on c:\ so it is:
Select Flash all
Go into download mode on the phone, connect the phone to PC
Refresh in MiFlash, select the COM10 device which is my connected Redmi 3
Click Flash
Then it is forever stuck on "Send hello response" I tried for few hours but nothing changed, I have to reboot the phone and I can try again, already did this like 50-100 times so I guess it won't work :/

I went to a friend with Windows 7 @ 64-bit as well, tried to do that and we had an other error:
the requested resource is in use.(0x80070aa: open serial port :\\:\COM3) or something like that

Is there anything else I can try :( ?
Anyone knows how to help me?