Windows Vista problem

Hello Hoi Kwok,
We regret to hear about the inconvenience caused, could you please share us a screenshot of the AVG interface from where you are facing issues, so that we can check and help you. Please click on the link to show how to create a screenshot : http://avgread.me/1aZxsAV
Also, please tell us the version of AVG you are using in your computer. Thank you.

Have AVG antivirus free installed on another laptop which runs Windows Vista. It ran ok until recently that it seems to be disabled automatically when the laptop is switched on and cannot be enabled again. If you press fix it, the problem is fixed for a few seconds and then it is disabled again. Any ideas?

Hoi, For your info, just in case that you are unaware, you can post the screenshot here in your topic. Click on 'Answer' & then click on the 'Image' [mountain symbol] & follow the instructions. 
AVG Guru

sorry, the images did not seem to show up on my browser. will try again with another laptop

Hello Hoi,
We are sorry to know that. We suggest to use this link to repair http://avgread.me/1BVxDSY your AVG program to fix this issue. Please reply back if the issue persists.
Thank you.