egui.exe crash after update on startup

Hoping to troubleshoot an odd event today. When my Windows XP computer started, NOD32 Antivirus 4 updated to the latest definitions this afternoon about 2 hours ago. I received a pop-up notification that the the update was successful, so I double-clicked on a desktop folder...and got nothing.

I was unable to highlight another icon on the desktop, so I assume that Windows explorer froze. Called up the taskmanager and found nothing unusual, so I eventually rebooted after waiting for 10 minutes and hearing no hard drive activity. On reboot the Event Viewer indicated that egui.exe had crashed at the time of the update.

Anyone have any idea about the cause to avoid the problem in the future? My only guess is that the default startup scan after an update includes the Desktop and somehow my attempt to open the folder caused a problem; seems like that should not happen though.

Other details:

- last update was successful 2 days ago on 7/28

- manually clicked on update after the problem occurred and received the message that I have the latest update

- [edit]: folder I was trying to open contained plain-text mbox files and probably got scanned on access