So for reasons i have to access an HDD without assigning a new volume or Drive Letter
and i can not reformat it is there a way to access the files maybe with some sort of program?

some fg for the answer

Boot a linux live disc.
Or
Use diskpart and rebuild the partition.

i dont use a linux and as far as rebuilding the partition
the disk drive has no partitions im using an external sata to usb

and would rebuilding the partition possibly corrupt data on the disk?

make a linux disc

If theres no partition you have raw data.
its already technically corrupt since you can't access it.

Linux live disk is the right answer.
Or usb
whichever.