problem to use 64gb pen drive with windows vista

hi. i have just bought a 64gb pen drive. i formated it using exfat, and now i cannot see the pendrive contents when i plug it to the PC usb port. i have already downloaded hewlett packard format tool utility and also hard disk low level format tool but utility. None of them work because it seems the computer does not recognize the pen drive. Although to disconnect it i have to "remove hardware securely", but it does not says "the hardware can be safely removed" until i unplug it from pc.
pc is a DELL inspiron 1420. windows vista home basic.
can you help me? thank you
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