I originally posted this in the HijackThis forum but they were unable to find anything so I have been sent here. I have seen this problem listed other times here and it seems like it's always turned out to be a malware problem but if it is, it wasn't found. (Info and link to that below). So here I am:
My task manager has disappeared.
CTL + ALT + DEL does nothing.
Reverse-clicking on the taskbar shows the task manager menu choice (not greyed out) but selecting that also has no affect.
Running taskmgr.exe brings up the error message that "Windows cannot find 'taskmgr.exe'. Make sure you type the name correctly and then try again. To search for a file, click the Start button, and then click Search."
When I try to run tasklist from the Run command, it briefly shows the DOS window and looks like it is running the command, but then the DOS window abruptly shuts down. Ditto wtih taskkill. (Run runs the msconfig or regedit commands fine.)
DisableTaskMgr under HKEY_CURRENT_USER in the registry key is set to 0 (default).
Remove Task Manager is 'not configured' in the group policy Editor.
As I said, it sounds suspiciously like a virus, but I ran MBAM, HijackThis, Runscanner, Kapersky, OTviewIt, DirLook, and a couple of VirSCAN.org scans and nothing was found. Here's the link in case it's useful.
Here's the link from the HijackThis forum
Any help greatly appreciated!