See if you would have followed the instruction in very reply on this thread !!!!    0142 indicates a mechanical failure of HDD  backup your data, the Hard drive is about to die, you need to replace it.  Your options are  2.5 Inch hard drive (the same one) 2.5 Inch SSD (better)  NVME SSD ( The best) 
Hello! I am new here...I have this dell laptop G3 3579 which is having a hard time booting up... When the laptop is turned on, it shows the dell logo then black screens immediately, and then after a while... (maybe a good 1 hour or more) the dell logo shows up again and slowly boots up to the windows...   I am hoping that someone would help me... because I need my laptop for study purposes ;-;
Dell laptop G3 3579 Slow boot up