So, I had Win7 installed on 128GB SSD and I planned to install Ubuntu 16.10 on my 1TB HDD. I made free space using EasyUS Partition Master and proceeded to install ubuntu from USB. Everything had gone(seemingly) smoothly but Win7 didn't appear on the grub list. I did partially repair it by following steps in the best answer(link) but after that my PC booted straight into the Win7. What's more it started to work incredibly slowly and stopped recognizing my sound card. Everything went back to normal when I have removed Ubuntu's partitions and restored C drive to a point before the installation. Now the point is I really need Ubuntu and I'm a bit lost. Could you please help me?
I'm using Z77A-G43 MoBo with the latest version of BIOS.