I don't think it's caused by AVG software. I think it's something that comes after AVG successfully loads.
In your case, I'd use Toshiba's system recovery to bring the laptop back to factory conditions. After that, you've got to reinstall all your programs and restore all your data from your backup. So it takes some time, but after that your brand new computer is brand new again.
Kees
I have a Toshiba laptop running windows 7 a couple of months old. I had installed the free version of AVG. Now when I start it up I get the windows error recovery screen followed by a black screen with a cursor.I have pressed F8 and gone to Advanced Boot Options and none of the options result in anything more than the same Black screen. Safe mode with command prompt finished loading at avgidseh.sys. I have emailed avg but got no response. Please can anyone help, my brand new computer is now useless.

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