Unbundled Loop said:
Yes, I did boot to Safe Mode. It to has a blank green screen with Safe Mode
at the top two corners, nothing in the bottom two corners, no icons, and no
Start bar.
Hmmmmm -- this _might_ be due to registry corruption.
You can revert to a previous version of the registry -- this MS
KnowledgeBase article describes the procedure:
http://support.microsoft.com/default.aspx?scid=kb;EN-US;183887
However, I would not do that until you are fairly sure that this is
really the problem (though, if you have not recently installed any
new hardware or software it should not cause any "problems" beyond
reverting personal settings, MRU lists and the like to thei state as
of the backup point you restore from).
I'm not sure how to advise you to determine that what you are seeing
really is due to registry corruption -- it's often as much one of
those "gut feeling" things as anything.
I recently saw a machine that turned out to have a bad disk sector
near the end USER.DAT (part of the registry). Surprisingly though,
Windows started just fine, despite the disk system error being
"obvious" if you booted to DOS and tried to copy that file. Well,
by fine, I mean without complaining or raising any error, because it
clearly had "lost" some rather critical user settings. Once the
"silent" disk error was discovered this was easily fixed by booting
to DOS, renaming USER.DAT, marking it system and hidden so it would
not be moved by future defrags and thus "protecting" the bad sector
from getting back into "usable" free disk space and restoring the
registry (as per the above) to the most recent backup before the
problem started. The trick in that case was discovering the disk
error, as the assumption that something that critical to the proper
functioning of the system would be brought to your attention was, as
is so often the case with MS systems, quite unreasonable...
About a week later I saw another machine that was not quite working
properly in Safe Mode, and was really screwed under a normal system
boot. Again, it turned out to be a corrupted registry -- this time
SYSTEM.DAT. It seemed, from looking through the file with a hex
viewer, that SYSTEM.DAT _had been_ (it certainly was not in that
state when I first got the machine to look at) cross-linked with an
INI file. My guess was that this "fault" was cuased due to a crash
(or perhaps more accurately, due to memory corruption before, but
leading to, the crash) and incorrectly "fixed" by the automatic
scandisk/chkdsk "run in auto-fix mode" during the subsequent system
restart. Again, no warning from the OS that, in reading through the
single most critical configuration file on the whole machine, it had
struck a patch of utter gibberish that was clearly not supposed to
be there...
The symptoms that led me to eventually track both these down were
very indistinct (and very different between the two cases) -- mostly
things that were "just wrong" and should not (be able to) work the
way they were. For example, on the second machine mentioned above,
a Toshiba laptop with built-in AccuPoint and an 800x600 LCD screen,
Windows insisted there was only a PS/2 connected mouse, could not be
made to see the AccuPoint for what it really was (though it worked
well-enough as an AccuPoint appears minimally like a PS/2-connected
two-button mouse), could not see a real PS/2 mouse plugged into the
PS/2 port (even with the AccuPoint disabled in the BIOS or with
"dual" or "auto-detect" mode set), and neither the video adapter
type (which was wrong but luckily worked on the actual adapter in
the machine in the 640x480 mode that it insisted on running), nor
its mode, could not be changed.
