Awast free version 6.0.1203

[Raghavendra]

I have been using the above sotware and one day suddenly this prom stopped running. I tried to once again reinstall it and the result is the same.
unsecured .Your systen is  not protected.Please use the FIX NOW to start protecting your system button. When I click to FIX Now I get the following error message.
The following components could not be started,
Mail Shield,IM Shield,P2P Shield,File System Shield,Web Shield ,Script Shield,Behaviour Shield, Net work Shield.
Please advise and guide me how I can rectify this and use your antivirus.
thanks

[Asyn]

Repair avast:
1. Control Panel - Add/Remove programs - avast!
2. Scroll down and click on 'Repair'.
3. Follow instructions.

[Raghavendra]

Repair avast:
1. Control Panel - Add/Remove programs - avast!
2. Scroll down and click on 'Repair'.
3. Follow instructions.

Thanks for your promt response and guidance.Despite running repair I get the following error message.
Unable to start scan
There are no more endpoints  available  from the end point mapper.
Please guide and help me.I may add however while booting my computer avast sacnned memory. I use win 7 ultimate 32 bit.