external hdd invisible to one of my 3 PC's ??

I have an external 2.5" hdd that is recognized by only one of my 3 PCs.
I have tried going through control panel>admin tools>computer mgt>storage>disk mgt as well as hardware devices route and the PC still cannot see the HDD.

Additionally I have reformatted the external hdd hoping that might but it did not

I have tried other ext hdd's with this PC and it sees them with no problem.

Any ideas as to what the problem may be?? Thanks for your help

 

What file system?

Size of the external hd that is not recognized on two computers?
What version of windows is installed on those computers?
Any popup or error message when you plug the device in? (I assume you are connecting it through a USB port).

 

When I formatted the ext hdd there were 2 options. I chose the mbr option

The pcs are all W7 Home Premium 64bit
The disk is a 160GB (WD Blue Scorpio ATA)
I am connecting through USB, have tried several cables, and there is no pop up or error message OR audible sound.... it is not recognized by two PCs and immediately recognized and operates normally with my dell14z

Again appreciate your assistance in trying to solve this mystery

 

I was looking for NTFS.
Does the Dell show a drive letter for drive? If the drive letter assigned conflicts with something on the other two computers, perhaps it is unrecognized. (I'm not sure on that because the one 2.5" hard drive I have, is not able to be used on any of my home computers that I've plugged it into). Change the drive letter to something way down in the alphabet then see if one of the other two computers can now see it.