Hi Dick
I am Dave, an Independent Advisor, I will help you with this . . .
Open Disk Management (accessible by right clicking your Start Button)
On that drive, for each partition, right click the partition and select 'Delete Volume'
When the whole drive is marked as 'Unallocated Space' right click the Unallocated Space and select 'New - Simple Volume' and accept the defaults
That should result in the drive being one large partition and you should have full access to use that drive again . . .