Locked up computer

Hello William,
Thank you for reaching AVG Support Community.
I sincerely apologize for the difficulties you are currently experiencing.
AVG TuneUp shouldn't cause this issue.
May I know the last changes which made on your PC?
Have you run any performance scans using AVG TuneUp? 
Have you updated any drivers on your PC?
May I know what is the exact error message is showing on your PC while it turning on?
Upon checking your account, you have a duplicate product of AVG TuneUp, If you wish to merge your AVG TuneUp subscriptions then confirm and reply to us.
Thank you.

did avg scan. it recommended an upgrade to fix performance issues. paid for upgrade and installed.  Now computer locks up. Have had to actually remove battery to restart machine twice now. Am doing it for the third time!! How can I  rectify this??

Thank you for your confirmation, William.
As it isn't recommended to share the product details over this post, we've sent you an email regarding it & to troubleshoot the issue.
Please check & revert to us for further queries.

Yes, please merge the TuneUp that are duplicate.
I  appreciate your help