Originally Posted by hafizimtiaz
You've got 4.4.3 update in OTA? Are you using Google Edition HTC One?
Bootloop after OTA generally results if your system is somewhat modified (like custom recovery or changed system files) and you forced install the OTA. You can flash stock RUU (exe or zip) and then try OTA again.
I'm not sure what update it was, it's not my phone. The phone WAS completely stock however. I thought I have to have Soff to flash the RUU
After some googling, I found the RUU, but I have to flash hboot 1.44 which I can't do because S-On. The only way to make S-Off is to have the phone working. So this is just a giant brick now, unless there's a way to turn S-Off from fastboot.