Sporadic hard drive intensely busy, apps stop responding

I'm not sure what started to cause this. My computer was working perfectly fine up until this week.
HP dv6 Pavillion laptop, 500gb with 40% free, Windows 7 with latest updates, 4Gb RAM.

The symptom is this: All of the sudden, applications start throwing the "not responding" state. I check my hard drive light and see it's on non-stop (no flicker). When I listen to the laptop, I hear the hard drive in a "loop" of click sounds. A bunch of rapid clicks for about 2 seconds that ends in a "double-click" sound, a pause, then repeats. It just keeps going. If I close down Outlook and a bunch of other applications, and wait, the pattern eventually stops and my laptop is functioning normally again.

I've run a disk defragmenter program and overall my drive showed to be in good shape. I also ran a disk surface detector and didn't find anything wrong, no bad sectors.

At first I thought Outlook might have been the culprit, but I've seen it trigger when something else is running, like Event Viewer.

So my question is... is my laptop suffering from a "partial" hardware issue? Or is it a software problem? I managed to get the task manager running when the busy hard drive issue popped up, to see what program was taxing the CPU, and... nothing. I couldn't get the Resource Monitor open, because it was just too damned busy.

My Event Viewer had a clutter of messages... but the only thing I saw peculiar were strings of about 15~20 "Bonjour Service" errors. I cleared everything out to start fresh and once this happens again, I'll note the time and see if there are any event entries that coincide that might shed some light.

Meanwhile, any ideas?

Thanks for the tip, GokAy.

I've booted up in safe mode and at first everything was normal. But when I went to look at the Event Viewer, the busy hard drive pattern started to repeat. So, definitely not a driver issue.

I'm running CHKDSK to do a full drive scan and see if there's a bad sector somewhere. I imagine if a bad sector cropped up and affected a system file, something like this might happen.

Are there any decent (and free) basic disk diagnostic and repair programs that you'd recommend?

Thanks.

I ran CHKDSK /F, and it claimed that no errors were found. I ran SFC /SCANNOW and it didn't turn up any critical errors.

Is it possible that there's a corrupt system file somewhere that Windows is simply not detecting?

Sounds like I need to run a more extensive low-level kind of disk utility. Certainly doesn't seem to be a driver related problem as it cropped up while booted into safe mode. But I guess it might not be a bad idea to run Process Explorer to see if there's any particular process actively accessing the disk.

I have a freshly updated anti-virus always running and do not visit suspicious sites... and I'm thinking this shouldn't be any kind of maleware or virus, because hard drive disk activity would be done with minimal effect on the operating system (last thing malicious people want is someone being alerted). The drive access noise being made has a definite pattern to it that repeats over and over, until some random point when it stops. But then it may kick up again at any time.

OK, the disk utility didn't find anything wrong...

When I was able to gain control for a few moments, I was able to launch the system process monitor and observe the Resource Monitor for the disk. I then launched the Event Viewer which often triggers the incessant disk activity loop.

Sytem Process ID number 4... heavy read/write.
Cause? System Volume information (Logfilre NTFS Volume Log) leads the charge with several other volume related processes.

When I scanned the Event Viewer System log, I saw something peculiar... a Warning for Wininit. "Custom dynamic link libraries are being loaded for every application. The system administrator should review the list of libraries to ensure they are related to trusted applications." THAT... is unnerving! What does it mean? I do have AVAST! and I found some people post that it may cause that.

There were some Windows Telemetry files flagged as problematic in the SFC /scannow log, which I was able to fix using a custom utility (SFCFIX.exe). Everything seemed fine, but I was able to trigger the endless hard drive activity again... just by going into the Windows System Events and clicking to view one of the nodes. I had created a shortcut to the Resource Monitor and launched it. System PID #4 has 137 threads launched. Disk I/O very busy with pagefile.sys.

Then I noticed something strange... I did not have Google Chrome running, but Chrome related processes are chugging away, especially with the "Safe Browsing Bloom" under User Data... whatever that is. I'm starting to wonder if Chrome is the issue here.

I have 4Gb of RAM... which has been suiting my needs just fine. System managed pagefile was about 7.5Gb. I figured if the pagefile had a problem, would be a good idea to rebuild it, so I set paging to "no file", rebooted, set it manually to 7.8Gb, then rebooted once more. Still happens. I have over 40% free drive space.

I'll have to run a memory check to be sure RAM is testing OK... but I suspect this isn't the problem.