Windows Security Center does not detect 3rd-party anti-virus softw

Hi,

I have problem with windows Security Center.

Recently I reinstalled widows on my two notebooks.
After reinstallation Windows Security Center does not detect any more my
third-party anti-virus software on both notebooks, in spite I never had this
problem before.

The OSs are Windows XP home SP3 on one notebook and Windows XP pro SP3 on
another notebook.
The anti-virus software is CA anti-virus v.9.0.0.194, which I use already
for 2 years.

In windows XP home the Security Center always shows that anti-virus is
switched-on, even if CA anti-virus is disabled or even completely deleted.
In windows XP pro the Security Center does not detect any anti-virus
software, in spite CA is installed and functioning.

I tried to solve the problem by repairing the Repository:
http://support.microsoft.com/kb/944175/en-us
This, however, does not give any effect.

I have also tried to rename or delete the Repository, in order to let a new
one be created.
In cmd:
net stop winmgmt
cd /d %windir%\system32\wbem
ren repository repository.old
net start winmgmt
OR
net stop winmgmt
cd /d %windir%\system32\wbem
rd /s repository
net start winmgmt

This action, however, always fails, as repository cannot be renamed or
deleted because it is used by other software.
I have tried to perform this in safe modus - the same result.

I posted this problem to Microsoft xpsecurity forum
http://social.answers.microsoft.com/...2-8363d1426b55
Unfortunately, I did not receive any respond.

Finally I have renamed Repository in windows XP home by using Unlocker1.8.9
in save modus.
As a result the Security Center has stopped to show that anti-virus is
always switched-on and shows now that anti-virus is not installed.
So the problem remains.

Could you pls. suggest how to solve the problem ?

Thank you very much in advance !