Alienware M17x R4 - Safe mode problem

Hi everyone. I'm having a big issue with my Alienware laptop being stuck booting into safe mode. At present, I can't log in or out of Windows and I don't have any option of changing users. Fyi, my Alienware is running on Windows 10.

This issue came about as consequence of a failed attempt to get rid of adware by "Serpens" (this one is going around as of recent). I used various adware detectors and cleaners, however it was still slowing down and even paralising my internet connection. So I thought that booting into safe mode and then running various scans and offline would be good option. However, I'm now stuck with Windows screen without any dialogue field. Instead there is only three symbols in the bottom right corner with Network, Ease of Access and Shut Down options. I've tried ctr+alt+delete, but there's no reaction. I've restarted it, a few times - no change. Went into "setup" and "boot options", but I didnt't manage to change anything.

I've been actually so far very happy with my Alienware M17x R4. It's been, and still is, a fantastic piece of equipment as I've been using it successfully for 2 and a half years. I've purchased it online from America and got it shipped to Australia. I understand that there is a good chance that I will have to factory reset it. Another problem though is that I have lost the original Dell box with recovery system drivers etc.

I would appreciate any suggestions very much in hope to resolve this issue, as I can't do anything with my laptop at the moment. The situation looks hopeless.

Thanks for your time and effort.

Kind regards