I´ve tried installing Ubuntu for the past week. I was given an "old" Win7 HP ProBook 455 G2, but only if I deleted all of the old user´s files. Since I wish to run Ubuntu on it, I said it was no problem. But then the problems started. This is what I´ve done so far.
Tried installing Ubuntu 15.10 - Got the soft lockup problem. Tried the prior LTS version (14.04.3), same issue. Tried installing Ubuntu 12.04.4 LTS, now I got somewhere! Came all the way to the actual Ubuntu installer, formated the drive but then I got an error telling me that GRUB couldn´t be installed. (I wish I could post the exakt messages but since I cannot get any crashreports from the computer, I´m out of luck).
To answer some questions: Yes, secureboot is off. Yes, the TPM is active. No, I do not OC, tried but it resulted in less stability so I decided to return it to it´s original state.
My problem now is that when trying to install 12.04.4, I recive the "Waiting for network config." Then it waits for "up to 60 more seconds" then a black, blank screen. The computer is still on though. This appears even if I try to "Try Ubuntu without installing" and even if the ethernet cable is connected.
Right now I have a computer with a formatted hard drive and no OS. Please help! I´ve googled extensively but without progress. I have some experience with the terminal and such but I´m in no way an experienced user.