Windows XP in VMware Workstation 7.1: Windows Explorer Keeps Refreshing

I was running Windows XP SP3 as a guest in a virtual machine (VM) in VMware Workstation 7.1.1 on an Ubuntu 10.04 (Lucid Lynx) host.  I had just installed a couple of freeware utilities when suddenly Windows Explorer began refreshing itself about every two seconds.  More specifically, it was refreshing the right-hand pane, showing files and folders, but not the left pane, showing the folder tree.

I thought at first it was a virus, but I was running antivirus software, and a scan with a different antivirus program turned up nothing.  Besides, I had just downloaded those programs from reputable sources (e.g., CNET) that supposedly certified them to be virus-free.

A search suggested this was a relatively common problem.  Several posts made me think it had to do with network drives, which in this case would mean the link between Windows and VMware.  I killed the VM, reverted to a previous snapshot, and started that, but the same thing was happening there as well.  I powered up a different VM in a different session of Workstation.  The problem was not occurring there.  I closed all sessions of Workstation and powered up the misbehaving VM in a new session of Workstation.  The problem recurred -- but then, after a minute or two, it stopped.  But then, after I used Windows Explorer some more, it resumed; but then it stopped again.

I downloaded the "Prevent Automatic Folder and Icon Refresh" registry edit from Kelly's Korner and ran that, and then rebooted Windows within the VM.  The problem was still there.  I took this to mean that *automatic* refresh was not the problem -- that, presumably, something was manually refreshing Explorer.

I tried displaying different drives' contents in Explorer, on the theory that maybe this was happening in connection with just one particular network drive.  That was not the case; it happened on all of them.

I wondered if a program installation was responsible for the problem.  But it was not clear to me how any of these would have been responsible for the fact that the flashing occurred within a snapshot that I had taken before installing them.

Then I came closer to what seemed like a possible answer.  I tried again to install the Microsoft Task Switch Powertoy.  I had tried before, and it had given me an error message, and the same thing happened again.  The error message was "Error 1606.  Could not access network location [gibberish]."  The gibberish was actually just a set of five squares with no characters in them.  It appeared that the installer was trying to access a network location whose name did not consist of valid characters.  Following advice, I checked the following registry keys for incorrect addresses:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders

I did find several bad entries in the second of those five locations.  I corrected those and rebooted the VM.  I was now able to install the PowerToy.  Unfortunately, the flashing was still going on.  I went into VM > Settings > Options > Shared Folders and switched that to Disabled > Save.  The flashing stopped.  In Windows Explorer, I tried to go to another network drive, but got the message that it "is not accessible.  The network path was not found."  I went to drive C (not a network drive).  Its contents displayed OK.  No flashing.  I set Shared Folders back to Always Enabled.  No flashing on drive C.  Flashing on drive D.  I tried C again.  The folders there would refresh once, immediately after being selected, but then not again.  In Windows Explorer's menu, I went to Tools > Disconnect Network Drive and disconnected drive D.  Drive E was still flashing.  I went to Tools > Map Network Drive and mapped D again.  It was flashing.

A Microsoft Knowledgebase webpage said that a somewhat related problem (flickering in the left-hand pane of Windows Explorer) could be repaired at HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer.  I had only a lowercase "policies" (not "Policies") key at that location.  Regedit would not let me create the uppercase version.  So I went into the lowercase "policies" key.  It did have an Explorer subkey.  I went in there and created a new key, NoRemoteRecursiveEvents, of REG_DWORD type, and gave it a value of 1.  I exited regedit and rebooted.  This step did not solve the problem.

I closed this VM and went back to the previous version, the one that did not flash.  I corrected the incorrect registry addresses (above) first.  Then I started reinstalling the programs that I had been installing when the problem began.  I went down the list and, what do you know, the flickering started when I installed FolderSize, and it stopped when I uninstalled it.  FolderSize calculates the size of folders, and apparently refreshes the screen while it does so.  After I uninstalled it, the problem went away.