Nick,

Explorer errors in unknown are nearly always the result of having unwanted
malware on the system, often a parasite of some form.

This might be a good time to download yourself a copy of the free Ad-Aware 6.0
from Lavasoft (http://www.lavasoftusa.com/software/adaware/) and also SpyBot
Search & Destroy (http://www.safer-networking.org/) and use them to check your
system for other commercial parasites remembering that they are only as good
as when you last updated their reference files. I also use a program called
BHODemon (http://www.definitivesolutions.com/bhodemon.htm that checks for
unwanted Browser Help Objects and SpywareBlaster
(http://www.wilderssecurity.net/spywareblaster.html) which can help prevent
some parasites getting a grip on your PC.

Just is case the problem is due to a new version of the CoolWebSearch parasite
you might want to download and run the CWShredder which targets that specific
parasite. Unfortunately neither AdAware or SpyBot seem to be able as yet to
fully detect all the various versions of the CoolWebSearch parasite as it
keeps changing. For more details of the CoolWebSearch parasite see
http://www.spywareinfo.com/~merijn/cwschronicles.html.

CWShredder, merijn's removal tool, can be downloaded from either:
http://www.zerosrealm.com/downloads/CWShredder.zip
or
http://www.spywareinfo.com/~merijn/files/cwshredder.zip

Finally if you still continue to experience problems download a copy of
HijackThis from (http://www.spywareinfo.com/~merijn/downloads.html). Create a
folder called hijackthis on C: and copy the file you downloaded to that
folder. Close as many applications as you can including all instances of
Internet Explorer and then run hijackthis.exe and post back the log, provided
that it isn't too long, to this thread, otherwise to the HijackThis Forum at
http://www.spywareinfo.com/forums/ and hopefully this will enable someone to
identify the cause of your problem.
--?
Mike Maltby MS-MVP



Nick wrote:

Every time I switch my computer on it comes up with an
error message which says "Explorer has cuased an error in
unknown. After this has come up I click close which is
the only option and then it will either keep coming up
again or it will wipe my whole desktop and just leave a
blank destop. It also stallys when I do manage to shut it
down as well.It will close everything down then it will
finally get to a black screen with a little flashing dash
in the top left hand corner of the screen.I dont whether
these two things are linked but there destroying my
computer.Please help!Thanks