Best way to "Undelete" a partition

[Markfw]

So I googled, and I am on my 3rd piece of software. Number one wanted $55 just to do anything. Number 2 abended when I tried to recover after scanning for 3 hours. Number 3 is still scanning 4 hours later. I was installing Windows 10, and mistook the old partition/drive from the data drive. The minute I saw that in Win 10 setup, I hit reboot. Too late, it did it ! So what do you all recommend for (hopefully) free or less than $55 software to simply "undelete" this partition ?

 

[JackMDS]

YMMV, it also depends on the size, how it was Deleted, and what was going on after.

Free - https://www.easeus.com/partition-recovery/index.htm

Less than $55 - https://www.partitionwizard.com/comparison/partition-magic-free.html

 

[Markfw]

One terrabyte HD. The one I was trying (number 3) looks like its free, and may have worked.(Remo Recover)

If not, I will try the one you linked.

 

[Lanyap]

I detect mainframe - abended.

I think I've used easeus before but it's been awhile. Most of the free ones will find the partition if it still exists but you have to pay to recover it.

You may also want to try to repair the Master Boot Record. Your partition may still be intact but the boot record is hosed. I've used it before to fix boot and partition problems.
https://neosmart.net/wiki/fix-mbr/