Making the big move

[efc]

When you start the installation process, there is a step that allows you to co-exist with Windows or other OS, and it allows you to pick the partition that it occupies. There is also a choice to delete existing OS and reformat the drive before installation.

Since you apparently wanted to reformat, I would reinstall. It only takes about 20 minutes and you should have a much more stable setup. If you want to try to correct bootloader first, do the following:
- choose Launch>Control Center>System Administration>Boot Manager.
- You will now click on the Administrator button and login as Administrator.
- Now you can choose the Default OS.