Open Excel --> Re-open Excel warning

[gg]

Hey guy's I have a setting problem and can't get the issue resolved.
When I open Excel, Windows tells me that excel is already open and ask if I want to open it again?

Prompt message:

aaaaa.xls is already open. Re-opening will cause any changes you made to be discarded. Do you want to re-open aaaaa.xls? Y/N

What is wrong with the file type setting's here?

 

[RoryA]

Is aaaaa.xls stored in one of your XLSTART directories or in a location specified as an additional startup directory?

 

[gg]

It is just a file in a folder. This occurs with all .xls files. regardless the folder they are in.

 

[RoryA]

Is this when opening Excel files from Explorer? If so, do you have Explorer set to open items with a single-click (under Tools->Folder options) whereas you are double-clicking?