Backed up Data Restore Causing External HDD to Show up as Two Drives

Hi

UPDATE: I have just found out that my new external HDD was partitioned during the data restore. It now has two partitions of 500Gb each. How do I merge them into one without losing the data? Alternatively, what do I need to do during data restore to stop the disk from being partitioned?

I hope this is the right section to post this.

My 500Gb external HDD, which was used specifically for storing data, crashed. I purchased a 1Tb external HDD to replace it. When I plugged it in, it showed as a 1Tb HDD, but the system assigned a different letter to it.

I restored the data that was backed up using AOMEI Backupper to the new disk. After that, I now have two external drives showing up instead of one - one with the new letter and another with the old letter. They are also showing only 500Gb storage each. The data on both drives is identical. The data is not mirrored, as if I remove a file from one drive (that has the new letter assigned), the file is not removed from the other drive. In addition, the other drive (with the old letter) is write protected.

I have a feeling that AOMEI Backupper assigned the metadata from the old HDD to the new disk, but really I am not sure what's going on and how to fix it.

I would appreciate any help in resolving this.

If you post a screenshot of disk management window, we might be able to advise.