Assuming the thumbdrives are formatted either FAT16 or FAT32 and the link is auto-populated to your desktop, you should be able to right click and mount the drive(s). Then, right click again and choose Actions> Change read/write mode> choose yes or no depending on intent. You should then be able to save to your drive. Once you're done, don't forget to unmount the drives to ensure the data is saved.

HTH

'Goon