Hi,
I have the Home version running on windows XP SP2. Recently i noticed that the standard shield is not running. And in fact, the Security Center in cintrol panel confirms this as its showing a warning that my antivirus program is not running.
The program is updating regularly and currently has 5 providers running: Instant Messaging; Network Shield; Outlook/Exchange; P2P Shield and Web SHield
How can i start the Standard Shield?
regards,
I should start automaticly.
Check the services for Avast and make sure they are all running.
Should be 4 of them.
(start > services.msc)
If they are, try a repair of Avast.
(start > control panel > software > add/remove > Avast > change/repair)
it is not starting even if a switch off my machine and back on. in the services list there are indeed 4 services: avast! Antivirus, avast! iAVS4 Control Service, avast! Mail Scanner (stopped), avast! Web Scanner.
I tried to make a repair as you suggested but with no luck 
the version that the security center is reporting is avast! antivirus 4.6.691 [VPS 0529-2].
What else should i try please?
Did you have another AV on this system, if so what?
How did you get rid of it?
Are there any error messages relating to avast when you boot?
In the services, ‘avast! Antivirus’ ashServ.exe, start it and change the Startup Type: to Automatic and see if that sticks.
no, avast is the only antivirus installed on my machine. I did not install any other antivirus before it.
the services is started and in the Automatic type already.
There are no signs of errors, niether when the machine starts up nor in the event viewer. Everything seems fine except for the security center.
One thing i noticed is that ashServ.exe is listed in the Processes tab of task manager. However it seems that the CPU counter remains 0 even if i try to open files from explorer. However, when i browse the internet the CPU counter goes up a little.
Maybe i should uninstall and re-install?
That sounds like the next logical step, uninstall, reboot, install, boot.
ok, that fixed it. 
Thank you for letting us know, a belated welcome to the forums.