If you’ve been reading my blogs lately, you’ll know I’ve been battling mightily with some vexing and puzzling stability problems on my primary production PC. In the past two weeks, I’ve tried nearly everything I can think of to bring this problem under control. My failure to find a convincing resolution is forcing me to plan for the unthinkable last ditch for Vista system repair: back everything up, blow away the system drive, then reinstall Vista and all my applications. Ouch!

I’ve only recently been able to figure out that losing explorer.exe is what’s causing my system to hang or freeze, because whatever is causing this problem is taking explorer.exe down before it can write an event to the event log. But the symptoms of Explorer problems are unmistakeable: inability to invoke applications, no response to Start menu selections, no access to Sidebar items, and no response to Alt-Ctrl-Esc or Alt-Ctrl-Del attention key sequences.

This has led me into a very interesting set of discoveries about Vista, albeit with some kicking, screaming, and colorful language. Searching on “explorer.exe crash Vista” led me to understand that there are at least a dozen well-known causes for this problem, chief among which are the following:

1. Some kind of malware infection or infestation (I’ve run all my local tools and also used housecall.trendmicro.com and have come up clean on all scores). I still haven’t taken the step of installing HiJack This and posting my logs at TrendMicro, MajorGeeks, or any other other good HJT support sites out there. This may very well be my next step…
2. Bad or incompatible graphics driver (not my problem, however, unless the latest NVIDIA 175.19 8xxx driver software is buggy)
3. Too many or ill-behaved Shell Extensions plugging into explorer.exe (I came across a great freeware download called ShellExView at www.nirsoft.net and used it to disable all non-essential Shell extensions, but I still can’t tell if it’s helping or not).
4. Issues with Family Safety settings in the Windows Live environment (I don’t use Windows Live).
5. Too many or ill-behaved Internet Explorer Add-ons (IE lets you mange these pretty well yourself, and I’ve now disabled everything except for two Java items: Sun Java Console and SSVHelper Class, and the Adobe PDF Link Helper; here again, it’s too early to tell if this is going to help or not).
6. Possibility of various corrupt or damaged Windows sytems files, most notably ntdll.dll, shmedia.dll, and numerous other multimedia file access DLLs. In response I ran the system file checker command line utility sfc /scannow, and it reported no integrity problems were found.
7. Issues with Volume Shadow Copy services interfering with file copy/move operations inside Explorer (I haven’t figured out how to test to see if this might or might not be a problem, but I supposed I could always disable the service and see if my system stabilizes)

But at this point, I’m trying to turn off or not to use anything non-essential on my system in hopes this will help me find the keys to stability. I have to keep researching this until I can find and fix it, or until I get fed up and go for the last-ditch solution.

Stay tuned! It may not be pretty, but it is proving very educational. I also found some very informative forum posts as I worked my way deeper and deeper into this morass, including one at the Windows Users Group Network (WUGnet), another at TechSupport Forum, a really good one at LockerGnome, and a final goodie at VistaClub.com. Along the way, I’ve also learned about and used some interesting and helpful tools, and some more good Windows troubleshooting and forensic techniques. Count on seeing plenty of resulting coverage in the weeks and months ahead!