internet explorer ("windows explorer is not responding")

Since the install of Vista SP1, my internet explorer does not function
properly.
While browsing, suddently the hourglass will come on and after 45 seconds a
dialog box appears that says Windows Explorer is not Responding.
Click Cancel, or Close the Program, or Restart the program.

When I click Restart the program it hangs for a bit, the taskbar goes away
for 10 seconds then reappears, then all is well for another brief period
until it repeats.

Sometimes when this happens when I dont even have an internet exp window
open yet , and hover over the start button , the hourglass appears, BUT I CAN
STILL RIGHT CLICK ON THE DESKTOP EXPLORER ICON AND OPEN UP the browser

2 spyware runs by PcDoctor and Norton have yielded no problems.
This is a laptop with factory installed vista and all the upgrades incl sp1

I downloaded 346270_intl_i386_zip.exe and ran that its a hotfix from
microsoft, but now i cant tell you the article number where I found it
because this website has rudimentary search engines

Windows logon availability determines whether the Windows logon process is
able to be completed successfully. The logon process is the interface between
the account for a user, process, or service and the computer that establishes
authenticated credentials for the account and allocates the appropriate
system and network resources. Windows logon manages the use of the secure
attention key (CTRL-ALT-DELETE) to initiate the login screen, load the user
profile on logon, and lock the computer.

Some Windows Vista functions may not work, or Windows Vista may stop
responding: http://support.microsoft.com/kb/929833

Per the Mark Ferguson reply I followed the instructions per article 929833
which after you run the scan asks you to run a find string of the log file in
the form of
--------
findstr /C:"[SR] Cannot repair member file" %windir%\logs\cbs\cbs.log
>sfcdetails.txt
----------
The .txt file returned as 0 bytes because there were no occurences of an
error message of this type "cannot repair...."
However I did copy the cbs.log file in explorer from the logs folder back to
my documents folder, and with Word, opened the file and did searches myself
for the word repair, but non existed with "cannot repair"

I'm not a wizard at reading this log file if I can email it to someone or if
someone can direct me I would appreciate it. The system continues to hang
after I first start up the computer and I get the hourglass, then eventually
the dialog box appears.

Here is one notice from the cbs log file.
2008-10-31 20:13:10, Info CSI 0000003f Ignoring
duplicate ownership for directory [l:58{29}]"\??\C:\Windows\System32\et-EE"
in component Microsoft-Windows-comdlg32.Resources, Version = 6.0.6001.18000,
pA = PROCESSOR_ARCHITECTURE_INTEL (0), Culture = [l:10{5}]"et-EE",
VersionScope = 1 nonSxS, PublicKeyToken = {l:8 b:31bf3856ad364e35}, Type
neutral, TypeName neutral, PublicKey neutral

I think the log file results have told you all it can. If you do not have
corrupt system files, Occam's Razor lets you look to your personal profile
files as the cause for a logon failure. I would create a new user account
and try to reproduce the error. You can copy the old profile settings to the
new one if you find the new one works.

Actually this problem bothered me quite a long time too, but recently I find functional software which can fix all these problems just with one click: tuneup360, maybe you guys could have a try.