Put this code in a Global Module. Call it from your Startup Form in the On Load or On Open event. It will check to see if the database's icon file is present. If not, it will see if the file is in the current (database) folder. If so, it will reset it. Obviously change the name of your ICO file.
Code
Public Sub CheckIconFile()
Dim db As Database, IconFile As String
Set db = CurrentDb
IconFile = CurrentProject.Path & "\MYLOGO.ICO"
If Dir(db.Properties("AppIcon").Value) = "" Then ' Icon file not found. Resetting it.
If Dir(IconFile) <> "" Then ' Icon file exists, update property
db.Properties("AppIcon").Value = IconFile
Application.RefreshTitleBar ' Refresh Access TaskBar logo
DoCmd.Close acForm, "MainMenuF", acSaveYes ' close/reopen main menu
DoCmd.OpenForm "MainMenuF"
End If
End If