1. Download and install a free version of the EasyBCD program, then run it.
2. Click on the Edit Boot Menu button, select the OS (ex: Microsoft Windows Vista) that you want to delete, and click on the Delete button.
NOTE: If the OS you want to delete from the list is the Default OS, then you will need to change the default operating system to another listed OS first.
3. Click/tap on Yes to confirm deletion.
4. The OS (ex: Microsoft Windows Vista) is now deleted.
5. When finished, close EasyBCD.