Dell firmware Updates restart cycles issues

Hello I have bought second hand dell precision 5570 which is quite new the issue is that it cannot restart after updating the firmware via windows update but now I disabled the firmware updates via windows update by disabling  the option from bios setup from updates and recovery section the UEFI firmware capsule updates after disabling it and creating registry in regedit but now the issue is my pc freezes sometimes and I think its because of my firmware is at 1.2.0 while the new update is 1.29.0 the issue is the I am scared of updating the firmware even downloading it from website cause I had to reprogram its Rom by a hardware technician and causes me much money if I download the firmware update from dell website will it work for me or it will be still take my computer to restart cycles have anyone of you been successful