Whan a drive is unreceptive to data and difficult to install it often helps to run a burn in test.
Still, you are installing now.
You can always shrink the C: drive down with a partition resizer and put in an extended partition.
E.G.
Then you can use Tweak UI to move the My Documents folder and sub folders to their own partitions.
Partition sizes are 10240,10240,20480, (MB) and the remainder.
Don't know about PowerMax unless your floppy diskette is a bit tired.