I just bought a sony and a kingston flash drive. ( both are 32 GB ). they were working fine but when i wanted to format them they became kind of dead, windows cant format them, and also couldn't format them with disk management. (error : windows was unable to complete the format ) also tried safe mode and formatting from another PC. they are not write protected. i have the problem with both of them. and now just the pop-up for USB stick and just their names appear but no capacity. win 7 x86. any advice ?!