My sandisk cruzer 4 GB pendrive ws working fine but now whenever i try to format\copy\cut it shows location 0 with used space 0 free space 0 what should i do

Your flashdrive usually shows 2 drives when inserted to your computer, one is the U3 drive and the other one is the removable disk drives. U3 drive is your separate partition for the U3 system and in order for you to store, copy, format your flashdrive, you should be selecting the removable disk drive, not the U3 drive. U3 is a read only memory drive that is responsible for your U3 to work (just like portable applications). Hope this helps.