PartitionMagic 8

With partition magic 8 installed on my pc, I get certain error messages when
trying to start it or get partition information.
In the first instance, the "Init. try failed - Error 100 :
Partition table is bad".
The second is "Disk and Partition Errors: Error MSG Box".
The box for the physical drive is green colored and empty.
It lists a total size of 2437.3 MB when I actually have 20Gb
Having been told by the supplier to reformat, I looked into the situation
and discovered that my drive is not partitioned yet, because I am asked
whether to use large partitions or not. I didn't proceed with it yet, but
suspect that this is my problem. Am I right?
Thanks for the consideration.

Harry, old and wants to be sure.