Sandisk A1 1 gb SD card not working

Sandisk A1 1 gb SD card not working.
write protected.
detecting in laptop and not detected by desktop

something occur bad in your desktop’s hardware.

What do you want to do? remove write-protection and make it workable again?
We don’t know exactly what’s the meaning of not working with your description. You may try following ways:
Run CHKDSK in CMD: *chkdsk : /f /r
Run hardware troublshooter.
Update or reintall SD card reader driver.
Run antivirus scan
Remove write protection on SD card
Then, you may check if it can be recongized on desktop.