I had this issue bugging me over the last few days that nearly made me tear out my hair. I had been away and shut down my machine to be a nice green environmentalist (I normally leave my machine running 24*7). When it started up everything looked okay but I noticed fairly quickly that some variable period after startup when I clicked on something on my Quicklaunch bar or when I double-clicked an application, I would get the Windows hourglass for a couple of seconds and then nothing. I couldn’t start any application even those associated with Windows itself like the task manager.
I had not installed anything that might have interfered with application launch, or at least not that I could remember. I did a spyware search using Spybot Search and Destroy, nothing untoward found. I did a system restore to before the time I went away, no change. I then thought that perhaps it was something in Spybot that was stopping the process launch, so I uninstalled the application, still no better.
The only cure each time it happened, was to select Shut Down from the Start menu and wait for it to close all the open processes. This would take a long time, and require me to manually intervene to OK the closure of the applications that had started as processes in the background. Often it would hang after closing all the applications and require me to hold the power key for 5 seconds for a hardware reset (if this happens, always wait for all your system toolbar applications to be closed first as they will have files open that could be damaged).
I was getting really irritated, mostly because no amount of google-fu would turn up the same issue with a solution. I started preventing applications from running at startup time trying to find the one that was being errant, nothing helped though.
In the end I set aside time to restart the machine and then started uninstalling applications I no longer used. I figured I was going to have to reinstall and I might as well make the backup beforehand as short as possible. Deleting the unused applications was cathartic but of course it didn’t help the real issue.
Eventually I got into the habit of starting the machine and immediately launching the task manager so I could see what processes were hogging the CPU or determine if something untoward was being launched in the background.
…And then I noticed the page file usage was high.
Somehow my large manually set Page File size had become System Managed and was set at 704K.
Using Control Panels, System Properties
then Performance Options
and then Virtual Memory
I altered it to 3070 which is well above what I should ever need and the problems disappeared. Fingers Crossed but it’s been three days without an issue with the machine running all the time and overnight AV checks, BOINC, Google Desktop Indexing etc running.
Mid July 2008: The issue came back for 2 or 3 days for no apparent reason. In my latest fit I upgraded BOINC from 5.8.16 to 5.10.45 and so far, no more problems. Is this the final solution?
Feb 2010: I still see this issue from time to time.