Must format disk, but works perfect in different PC

Yes indeed FSBTech, your pen drive shows as RAW, for what reason still eludes.

Fireberd's personal experience of course is a pointer to be noted. But I shall come to that later.

For now let us see whether removing the active flag in your pen drive matters in any way.

Install and run MiniTools Partition Wizard Home Edition 8.1.1 with this pen drive plugged in. Free download Magic Partition Manager Software, partition magic alternative, free partition magic, partition magic Windows 7 and server partition software - Partition Wizard Online

Rightclick on the Pendrive in PW > Modify > Set inactive > Apply.

Once the action is finished, safely remove and plugin your pen drive again. Has it made any difference?

Reverting to Fireberd, we can try a fresh install of the OS on your laptop and check whether the problem is resolved. In case it does not happen, may be we have to blame a hardware fault. But I would wait to have opinions of other experts here on such a reinstall or any other suggestions to resolve the problem.

Do you have the Recovery Disks for your Acer Laptop?

The only other thing I could suggest, only if AFTER removing the Active flag the problem remains, is to use Partition Wizard to rebuild the MBR on the stick.

OK, here is something that flashed in my mind.

Check whether automount is enabled. ( It is possible that somehow it got disabled)

Run diskpart as administrator. Type automount <enter>.

If it does not say automount is enabled, type auotomount enable <enter>

That should enable automount . Quit diskpart. Plugin your external drives and check whether those get a drive letter and you are able to access the drives.