new disk connection issue

I have this new USB disk, formatted in exFAT. I have many other disks (Seagate and Western Digital mostly), and they have no significant issues.
But this one, when I start my main computer with this disk connect, it hangs on startup of the computer. I hear the disk spinning, and the screen remains black for as long as you want.
It seems he wants to boot from it, but still never actually does. No error is thrown whatsoever.
I removed the files which are in the root of the disk, and I also removed a System Partition on that disk. The latter I suspected as being weird to be there, but after this, the behaviour is exactly the same.
How do I use the disk then ? Well, I just have to connect it after booting into Windows.
But the things is that I don't like unlogical and explained behaviour, in particular if it prevents me to bounce my computer.
There is no other disk (in a series of some 20 USB external disks) that has this behaviour.
So the question is : what is going on ? How do I prevent this behaviour ?

Bayern said:

I have this new USB disk, formatted in exFAT

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Please provide maker/model and size of drive.

It's a Seagate Expansion 6TB HDD

Bayern said:

I have this new USB disk, formatted in exFAT

Click to expand...

Then I an confused why it is formatted as exFat. According to Seagate it comes pre-formatted as ntfs. Did you purchase it from a reliable source ie Amazon NewEgg BestBuy,etc. Is it a used drive?
I would suggest formatting it as ntfs unless you plan on using it also with a Mac..

glasskuter said:

Then I an confused why it is formatted as exFat. According to Seagate it comes pre-formatted as ntfs. Did you purchase it from a reliable source ie Amazon NewEgg BestBuy,etc. Is it a used drive?
I would suggest formatting it as ntfs unless you plan on using it also with a Mac..

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The exFAT format is to be compatible with Mac as well.

The drive is a new drive, and from a reliable source.

Don't plan to use it for a Mac but I would like to know if this disk is a bootable drive or not. I didn't make it bootable, that's for sure. If I format it, that setup would be lost, but I will format it anyway.

Checking its specs, it appears that a Seagate Expansion drive would come from the company formatted as ExFAT to allow read/write access from both Windows and MacOS.

The partitions you mention seem to be different from what I'd expect, though.

If it was mine, I'd probably use DiskPart to remove all partitions from the drive, create a single partition that uses all the space on the drive, and quick format it as NTFS or ExFat. I wouldn't set the partition to Active.

I might also check my BIOS settings to be sure that it defaults to booting into Windows.

bobkn said:

it appears that a Seagate Expansion drive would come from the company formatted as ExFAT

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Not according to Seagate. It comes formatted for windows.

glasskuter said:

Not according to Seagate. It comes formatted for windows.

How to use your Seagate Expansion Drive | Seagate US

This article covers how to use your Seagate Expansion Drive.

www.seagate.com

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Go to the link I provided. ExFAT is explicitly mentioned. (Scroll down, or search the page.)

The drives are supposed to be Windows and MacOS compatible, right out of the box.