First point: To support more than 2.2 GB, the disk must be formatted as GPT, not as MBR.
Second point: Even if the disk is formatted as MBR, you should be getting 2.2 TB, not 746 GB. The fact that this is not happening could point to a problem with the firmware.
You should first check for BIOS and USB controller firmware updates,as well as update for the USB mass storage driver.
In the case of the disk's firmware possibly being damaged, I hesitate whether to point you to the article Restore factory Hard Drive Capacity, since the utility described there can brick your drive. There is no guarantee that it will work correctly on your disk model.
This could also be a problem with the USB bridge on the motherboard, which problem belongs more in a computer repair workshop. Have you ever successfully used a USB with more than 746 GB on it ?
If the disk is still under warranty, it might be safer to exchange it for a new one.
Trying to analyze, the problem can only be :
- Windows driver
- disk firmware
The tests you can do :
- Check for Windows driver update (from disk manufacturer website), or try formatting and testing it on a recent Linux live CD
- Check for firmware update / ask vendor to replace the disk
- Try another cable of good quality
As a last resort, and only if the disk is exchangeable by the vendor if it becomes unusable,
you could try the utility in the "Restore factory Hard Drive Capacity" article.
I have already counseled it several times on this forum and it did the job, but this is always a risk.
But I must say that in view of your comment, this is looking more like a bad disk.
Question: What is the exact model of the disk ?