This can be caused by a blank entry, such as can be left behind by an incomplete program removal, in the HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run and/or HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run keys.
System32 Folder Opens When Logging on to Windows click here;en-us;170086
if you don't want to fiddle in the registry then download a vbs file on
Line 260. click on "System32 Folder Opens Upon Boot" click here
Thanks all - Still no joy. After clicking on the "system32 folder opens on boot" shortcut, I get the following message which prevents me installing the fix "iexpolore.exe on windows home edition service pack 1 cd is needed"