Caot boot into Windows 10, GRUB error

Hello everyone, first post here. I have come into some sort of issue after I installed Linux on a USB Drive.

1. I created a bootable Ubuntu 15.10 on an exteal USB stick.
2. I then used the stick to install Linux onto my exteal Seagate HDD
3. During the install, by default, the bootloader was selected to be installed on my SSD which also contains Windows 10
4. Install completed but since then whenever I boot to my inteal SSD which contains Windows 10 I get the following error

error: no such device "several numbers" grub rescue>

I looked around online on about 10 different websites and nothing worked. I attempted to delete any traces of Linux from my inteal and exteal drives, unplugged every devices, reset my CMOS and I keep getting that error. I attempted to repair Windows 10 using the Windows 8 Install DVD. I have attempted to erase the Linux volumes using command prompt on Windows but nothing does it. I keep getting that error over and over again and there is simply no way for me to boot into Windows 10. It seems grub is inside my UEFI or something as it messes up to boot order and prevents Windows 10 from booting.

Any help would be greatly appreciated. Been fighting with this for about 3 hours.