Gio,
I don't really understand what you mean. Here are the two options
First
1. Delete the directory C:\opentelemac-mascaret\v6p3
2. Download the latest version of the installer (updated a week ago)
www.opentelemac.org/index.php/component/...p3-windows?Itemid=54
3.Re-run the installer and send me a screenshot of the error.
Next
If you have done that already (and if you used the latest version of the installer) you should have at least Telemac shortcuts created on your Desktop.
Please confirm you have these shortcuts or not.
Juliette