Dell SupportAssist always stops working even after multiple reinstalls

Hey guys, I have some problem with my Dell SupportAssist software. I've gone through multiple forums and had done uninstall and reinstall procedures, support via email, chat or phone doesn't work because my service tag and the express service tag "can't be verified". I'm out of options and I'm tipping towards clean installing my Windows. There's also a problem with my Dell Update App and the Dell Costumer Connect, they're not working/not opening. Please help me out. Thank you.

Dell Inspiron 14 3443

Windows 10 HSL ver.1511 build 10586.71, 64-bit

BIOS A07