Scan hangs at 28%

Other posting (https://support.avg.com/answers?id=906b0000000D5OhAAK).
AVG Guru

I'm sure this question has been asked but I haven't seen the answer yet. Probably just haven't looked well enough yet but I'm running out of patience trying to fix it on my own so I'll ask again.
When I try to run a full computer scan with the AVG Free 2015 edition it hangs up at 28%, while scanning the registry, and will not proceed any further. I am running Windows 7 Home Premium, SP1 with all current updates. When this happens it also will not allow me to stop the scan or shut the program down, I have to use task manager to kill it. I have run the sfc /scannow utility, no problems, Malwarebytes, no problems, Microsoft's system security scanner, no problems. Also re-downloaded AVG and did a "repair" installation. I do not think there is any infection on the system and AVG seems to be working OK except for this inability to complete a scan. Any ideas on where to look and what to look for would be appreciated.

Other posting (https://support.avg.com/answers?id=906b0000000D5OhAAK).
AVG Guru