can't update important files and services while the system is using

First of all - reset the services to their normal settings.
then


Open Windows Update
Click on Change Settings
Select 'Never Update...'
Click OK
exit Windows Update
Now open Windows update again
Click on Change Settings
Select 'Update automatically'
Click OK
exit Windows Update
Open Windows Update, and do a manual Check for Updates.

Open an Elevated Command Prompt, and run the following commands

NET START BFE
NET START BITS
NET START WUAUSERV
NET START TRUSTEDINSTALLER

post the results

Here are some instructions to make life easier :)
1) To open an Elevated Command Prompt Window (the ECP window), click on Start, All Programs, Accessories – then right-click on Command Prompt, and select Run as Administrator. Accept the UAC prompt.
2) To run the commands easier, highlight the block of commands, and right-click on the highlight – select Copy. In the CP Window, click on the black/white icon at top left – select Paste. The commands will run but may not complete the last command, so hit the Enter Key once.
3) To copy the results... click on the Black/White icon in the top left, and select Edit... 'Select All', and hit the Enter key - then use Ctrl+V or r-click+Paste to paste it into your response.

That looks normal.


Please run a full CHKDSK and SFC scan....
Click on Start > All Programs > Accessories
Right-click on the Command Prompt entry
Select Run as Administrator and accept the UAC prompt - the Elevated Command Prompt window should pop up.

At the Command prompt, type
CHKDSK C: /R
and hit the Enter key.

You will be told that the drive is locked,
and the CHKDSK will run at he next boot - hit the Y key, and then reboot.
The CHKDSK will take a few hours depending on the size of the drive, so be patient!
After the CHKDSK has run, Windows should boot normally (possibly after a second auto-reboot) -

then run the SFC.

SFC -System File Checker - Instructions
Click on Start > All Programs > Accessories
Right-click on the Command Prompt entry
Select Run as Administrator and accept the UAC prompt - the Elevated Command Prompt window should pop up.
At the Command prompt, type
SFC /SCANNOW
and hit the Enter key

Wait for the scan to finish - make a note of any error messages - and then reboot.
Copy the CBS.log file created to your desktop (you can't manipulate it directly) and then compress the copy and attach it to your reply

No CBS.log file was created. The following appeared at the end of scannow:

Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation. All rights reserved.

C:\Windows\system32>sfc /scannow

Beginning system scan. This process will take some time.

Beginning verification phase of system scan.
Verification 100% complete.

Windows Resource Protection did not find any integrity violations.

C:\Windows\system32>

P.S. Same message as my original query still appears when I check for updates.

Please run the CheckSUR tool from http://support.microsoft.com/kb/947821
(you'll need to look in the details for Method 2)

Then zip the CheckSUR.log and upload it to your public SkyDrive so I can take a look - post a link in your reply.

The tool can take anywhere from 5 mins to a couple of hours to run (or 'Install') depending on how much it has to do, and may exit silently - it may appear to freeze for most of that time, but be patient.

Did you not bother to read any of the article?

The CheckSUR log is at
C:\Windows\Logs\CBS\CheckSUR.log