The external USB drive suddenly became Write protected. How to fix?

Question

Hard disks

The situation is this .. I don’t know how it happened, but an external 60GB USB drive switched to write-protected mode.
I thought something was wrong with the drive until I accidentally connected it to another computer.
As a result, everything is OK, and it is written and read.
But! when connected to the first computer - everything is the same. Write or format - does not work.
So it's in Windows? (Windows 8)