This method will convert your invalid dynamic disk into basic disk without losing any data and recover all files on your hard disk.
1. Download TestDisk , install and run the program.
2. Select Create (Use your keyboard arrow key to select)
3. Select the hard drive you want to change to basic disk and select proceed and press enter.
5. Select Analyse
6. Select backup, then select proceed.
8. Now select Write the press Y on your keyboard to confirm.
9. Reboot and now you will be able to use your disk again.