I was changing the drive used as a disk quorum today and received the following error at the end of the wizard in Failover Cluster Manager;

Failed to configure Node and Disk Majority quorum with '[Disk Group Name]'.

I then noticed the drive I was trying to add was in the “SQL Server (MSSQLSERVER)” group and not in the “Available Storage” group. To resolve this I went to the “Server Server (MSSQLSERVER)” node under “Services and applications”. Under the “Disk Drive” section I right clicked the drive I wanted to use for the Quorum and selected “Remove from SQL Server (MSSQLSERVER)”.

This made the drive appear in the “Available Storage” group. I was then able to successfully complete to wizard to reconfigure the quorum.