Windows 7: My Windows 7 Hates the Internet!

Hello Doctor,

I'm hoping that you can help me to resolve my PC woes. My machine frequently locks up when browsing the Internet. I recently performed a clean install of Windows 7 64 Home Premium back in December 2009. It had been running like a dream up until mid-April which is when my problems began. Regardless of which browser I use (Firefox, Chrome & IE) my machine will freeze up and stop responding to keystrokes & mouse-clicks, leaving me with no alternative but to hit the reset switch. This problem occurs seemingly at random. It can happen when first launching a browser or anywhere between 5 minutes to 3 hours of browsing the web. My Windows Event Log reveals little except for the fact that I've frequently powered off my machine improperly (reset when it crashes).

What's more, a quick search on the Internet reveals that there is a large number of Windows 7 users spanning a wide variety of hardware configurations that are also experiencing this very issue and like me, have yet to find an effective solution.

My hardware is now 2 years old & aside from my videocard upgrade in January remains the same as the day that I built it. I've ran a bevy of Spyware and Antivirus scans all of which have turned up negative. In addition to staying current via Windows Update, I have also updated all of my drivers, my BIOS, Java, Flash, and all browser add-ons and extensions. I have tested my memory using memtest86+ and the Windows 7 Memory diagnostic tool. Hard drive diagnostics also come up clean. I have tweaked my memory timings and voltages to match the manufacturer's specifications and I should also mention that I defrag religiously and have never overclocked this machine.

Other things I've tried in desperation...

1) Ran chkdsk /r
2) Ran sfc /scannow
3) Disabled all browser extensions & add-ons
4) Uninstalled Java, Flash & MS Silverlight
5) Changed power settings to "High Performance"
6) Disabled Internet Protocol Version 6
7) Loaded a previous restore point (which only reached back a few days, not far enough).
8) Tried the process of elimination approach to disabling services & was unable to pin down an offender.

Normally I'd be inclined to believe that this is the result of faulty hardware were it not for the fact that my crashes only occur when I'm browsing the Net. If I'm gaming, encoding video or running any other form of application my machine runs flawlessly and without issue. If I weren't so stubborn I would have re-installed my OS by now (though I hate to admit defeat). In researching this issue I have learned from the experiences of others that this problem is not likely to go away even after performing a fresh re-install.

I'm banking on the fact that someone in the MaximumPC lab has heard of, encountered or perhaps resolved this issue at some point in the past. I desperately require your expertise and guidance to determine what my next steps should be. Anything that you can do to help would be greatly appreciated!

My current specs...

- Windows 7 64 - Home Premium (OEM). Version 6.1.7600
- Intel Core 2 Quad 9450, Rev C1.
- EVGA Nforce 780i SLI
- 4GB OCZ DDR2 PC-8500 Reaper HPC Ram
- Sapphire Radeon 5870
- WD 300GB Velociraptor 16MB Cache (WD3000GLFS)
- Seagate Barracuda 1.5TB 7200.11 32MB Cache
- PC Power & Cooling "Silencer" 750 Quad (S75QB)
- Creative Sound Blaster X-Fi Xtremegamer SB073A
- Samsung SH-203B 20X DVD Rom

Currently running: Microsoft Security Essentials & Zone Alarm Firewall Pro

As a subscriber to MaximumPC magazine I've sent the following email to their "Ask the Doctor" mailbox. I'm also posting this here in hopes that someone might be able to help. Should I happen to receive a response from the MPC Doctor, I'll be certain to update this thread if they can assist me in finding a working solution: