Check in your registry under HKCU\Software\Microsoft\Windows\CurrentVersion\Run, HKLM\Software\Microsoft\Windows\CurrentVersion\Run, and see if there are any entry lines that are listed as "". Delete them. I had a system do this same thing and that is what fixed it for that system. These lines are for programs that are removed and moved on the system and at bootup it is trying to find them. Do not remove any lines that point to programs that you know are on the system even if they have the "" in them. Backup registry entery before you delete it just in case something gets missed up. It could also be one of the above too.