I have noticed this also, and have no good answer. However sometimes a restart can be avoided: Double-click the AVG icon (grayed out). It will bring up a window; at the bottom is a section entitled, "Anti-Virus." Click the "Update" button and follow the next prompts. This will install the latest updates, and often a restart is not then required.
If the problem persists, you may want to consider installing Avast! antivirus instead, from www.Avast.com.
This appears to be just as good. The only thing I don't like about Avast is that it requires an e-mail address.
David L. Smith, MD