When installing or uninstalling windows packages I receive the message
" The installation package could not be opened.Verify that the package exists and that you can access it,or contact the application vendor to verify that this is a valid windows installer package".
I have removed and installed Windows installer V3, carried out numerous registry cleans and reinstalled SP2 to no avail. MS advice is just to reinstall installer which has I,ve said dos,nt help.
I,ve tried to install the installer clean up utility but the fault prevents it.

Try downloading the Installer Cleanup Utility in Safe Mode with Networking.

You were able to reinstall SP2?

Did this problem only surface after that?

No it was there before reinstalling SP2. I,ve carried out all the usual unreg rereg and local service checks.Do you think this could be a home network problem?.
The fault showed up when I attempted to install Kaspersky IS and set about uninstalling Norton.

Further to my problem. I have now discovered that the redis version of Windows Installer will not work if SP2 is installed so I,ve removed it and rerun SP2. I still cannot install any windows packages or uninstall the ones I have. I have searched for c:\Windows\Installer folder without success.
During search windows installer keeps trying to install something???
The same installation error message as before comes up even in safe mode so I could,nt install the reg clean up facility.
Can I create a new installer folder for the msi files?