I would do a full disk image to your spare drive first (back up)
Then I would create a small secondary(extended partition) of 100MB at the end of your and within your recovery partition. (The limit is four PRIMARY partitions).
Copy the HP_Tools data into that partition freeing up a primary partition. it will be drive F for now but see below.
You can then delete the old HP_Tools partition Leaving just three Primary partitions and relabel the tools as E
You can the move (if you really need that 100 odd Megabytes ) the partitons up to fill the free space.
Now with only three Primary partitions you can split you C partition as you wanted.
Then I would create a small secondary(extended partition) of 100MB at the end of your and within your recovery partition. (The limit is four PRIMARY partitions).
Copy the HP_Tools data into that partition freeing up a primary partition. it will be drive F for now but see below.
You can then delete the old HP_Tools partition Leaving just three Primary partitions and relabel the tools as E
You can the move (if you really need that 100 odd Megabytes ) the partitons up to fill the free space.
Now with only three Primary partitions you can split you C partition as you wanted.