Computer boots up slower then normaly and with a blackscreen

Hello all

I have a problem. I downloaded a wrong thing wich i knew it would be a virus or something else.First off my computer was full of adds but i got rid of them quickly.Then when i wanted to boot up my computer the other day i had to wait longer then normal (I have an SSD and it was slow) . When it was done booting the only thing that i had was a blackscreen.The temporary solution is to end the task "Shell Infastructure Host" in the task manager.

Does someone maybe know what this is and how i get rid of it ?