Sony NW-E405 MP3 Player "pen drive shows bytes" Questions

pen drive/mp3 player capacity I have purchsaed a pen drive/mp3 player of 512 MB capacity. After a certain time it show capacity of 119 MB only. It show 2048 bytes in each allocation unit & 61240 totol

...pen drive is WRITE PROTECTED.I have check properties there it shows size of 0 bytes(used as well as free space).Please help me. Your pendrive is infected with Autorun.inf virus to remove this virus ...