Computer locks up when OC'd

[NysoO]

Hey guys!

Let's start with some specs:

Mobo: XfX 780i, P08 bios (latest)
Cpu: QX9650
Gpu: 2x 8800Ultra
Hdd: Western digital raptor 10k
Soundcard: Creative X-fi titanium fatal1ty pro
Memory: 4x 1gb OCZ 9200 ddr2

So, now to the problem. When overclocking, the computer hangs up, ALWAYS just after you've logged into windows. Now the wierd thing is that after I've rebooted and logged in again, the computer never hangs up. It's 100% stable. I can play games and benchmark etc. But after I've logged out or shut down the computer during the night, I have to repeat the process I described above.
Start the computer, log in, it locks up. Restart computer, log in, and then it's 100% stable again.

It doesn't really matter how much I overclock, as soon as I change any settings I get this symptom.
I'm currently running it at 10x400 1:1, which gives me an overclock to 4ghz.

I would really appriciate some help on this.
Thanks!

[Leeghoofd]

PSU dying ? Or some component that needs a kick in the nutts to get going full blast

[PsYcHoNo0b727]

What is your PSU? I might have missed it in the post, but it sounds like either your PSU is dying, or is unable to handle the load from your OC'd CPU and all your other components.

For your rig, I would recommend using at least an 850w PSU. I'm purely speculating here as to what the problem is though.

[NysoO]

Well I don't really think it's the PSU. I've got a HX1000 so it should be able to deliver plenty of power.
Also as I said, I can let the computer be on all day with the log in screen displayed. But as soon as I log on, it locks up, and I have to restart it and log in again. And after that it'll be 100% stable.

[PsYcHoNo0b727]

Well I don't really think it's the PSU. I've got a HX1000 so it should be able to deliver plenty of power.
Also as I said, I can let the computer be on all day with the log in screen displayed. But as soon as I log on, it locks up, and I have to restart it and log in again. And after that it'll be 100% stable.

Hmm, when you do get the computer on to the desktop, try disabling the log on feature so that windows loads without having to have you log on and see if you still get the lock up.

[NysoO]

Tried it, no difference there. It locks up just as it is about to login to windows.

[Leeghoofd]

pull out the Xifi and remove it's drivers...