Control Panel tries to load then disappears

Vista basic Home Edition Dell Inspiron 530 desktop. The PC is under a month old as it was sent as a replacement for previous faulty system.
Macafee AV installed, Windows defender.

Trying to open up Control Panel either via Start menu or desktop icon and the window briefly starts to appear (1 second).
I have deleted the icon and navigated to CP through explorer and clicked on Appearance and Personalization, Change Desktop Icons and re-created an Icon.
Rebooted and before shut down this message appears: explorer.exe - application error The instruction at Ox00269931 referenced memory at Oxc277f29d The memory could not be written. Click on Ok to terminate the program.
Is this related to the CP problem?

We have only used the Internet to download McAfee AV updates and Windows Vista Updates.

Any thought or explanations would be appreciated.
G

 

See if it happens in Safe Mode.

 

Will do Won't be visiting my Dad's pc until Wednesday.

G

 

CP loaded up in Safe Mode, but in normal mode. It is intermittent. Loaded up fine after reboot. Not ideal having to reboot every time we switch on PC.
G