Greg, Interesting… Have a look @ this link (https://support.avg.com/answers?id=906b0000000D45xAAC).
AVG Guru
On removable drives, the real-time scanner will scan and lock the usb drive even if the Removable drive scan is disabled. Windows 7 keep saying drive can't be safely remove because another program is using it. The only way to safely remove it, is shutdown the computer. The only program I recently installed was Free Avg 2015.
Greg, Interesting… Have a look @ this link (https://support.avg.com/answers?id=906b0000000D45xAAC).
AVG Guru