Need help with computer freezing and no internet connectivity

Running from the HDD currently, but also worked just fine with the stick. And I've also been trying to fix the internet this whole time, when I came across something. While configuring the network settings, the whole entire apartment's internet stopped working and was unavailable, and as soon as I took the ethernet cable from the PC and hooked it back up to my laptop, it started working again. Very strange...

Maybe an electrical problem on the NIC? Do you have another one?

Yeah, back home I had an old NIC laying around I was able to use, and I had the exact same problem with that as I do now. But at least now I think I can pinpoint it down and assume it's some sort of motherboard issue (I DID buy it from ebay, so I was taking a gamble there). Maybe a different BIOS update would fix it, who knows.

This.

I'll have to resume tomorrow, don't want to bring down my whole apartment's network again while everyone is online XD

@anon54210716 Thanks for your suggestion hope it will really work.

Finally figured out what was causing the issue, although have no idea why it was doing it. I decided to swap out the Q8300 for a Pentium D 945, and everything works flawlessly. No stutter, internet both wired and wireless works fine, everything is okay. Any explanation for this? Also since I plan on getting another quad core to replace the speculated faulty Q8300, any CPUs I should avoid?

Maybe you should update the bios and then test the q8900 again.