You may load rollback data (if saved when applying previous changes) and thus undo the last changes. Also you may use the command to load changes which were dumped to a file instead of applying to the disk.
You may dump changes to a file instead of applying them directly to the disk. Later you may reopen the disk and load all unapplied changes from the file.
Group redoing the last changes.
Discard all unapplied changes.
Write all changes to the disk. For changes to take effect in operating system you may probably have to restart computer. Under Windows you may not be allowed writing to some disk areas used by volumes - see Volume locking for details. Some antiviruses may also block direct writing to disk. Under Windows you may also try interface option IO SCSI to circumvent some restrictions.