If you search in Windows Explorer (or in the command prompt) for avgdiskx.exe and avgidsdriver.exe, in what folder do you find them? if it's the regular AVG-folder, they are part of the antivirus program. If they are in the Windows folder, look at the details tab in their right click>properties to see what programs it are and who made them.
http://social.technet.microsoft.com/wiki/contents/articles/13469.event-id-7026-the-following-boot-start-or-system-start-driver-s-failed-to-load.aspx shows this error means the files aren't where they are expected. Did you check that? Maybe reinstall AVG?
Win Vista.Desk Top:
Boot-Start System Fail to Load. AVGDISKX and AVGIDSDIVER. Event ID: 7026.
Is this a part of Avg Antivirus Program? Freezes on start up, if I try and restart to soon it will not start at all, sometimes the desktop makes a beeping noise. I can wait a while and boot up in safe mode. Can I uncheck in the start up manager services? If its a part of Avg Antivirus Program will it still protect with service unchecked?