Computer reboot when i log user account

Hello, first of all im sorry for my faults, im writing from my ipad and i m not native.

So since today i cant start my computer. First it starts normal and when I log in my user account ( obly one and administrator of course), i type in password but after that my scrren gets black and my computer reboots.

After several tries i got this message:

Pic-Upload.de - image.jpg

and when i click okay
i get this message:

Pic-Upload.de - image.jpg

basically i cant do anything now i may can go to bios but i lack of experience with that :/

i hope some smart people are able to help me :p

greeting and merry christmas

tailz