Try using diskpart to format your flash drive.
1) Open a command prompt (run as administrator).
2) Type in diskpart and press enter
3) type in list disk and press enter
4) use the select x command to pick your flash drive (substitute x with the corresponding disk number of your flash drive in the list) and press enter
5) type in clean and press enter
6) type in create partition primary and press enter
7) type in active and press enter
8) type in format fs=ntfs label=MYFLASHDRIVE quick and press enter
9) type in assign and press enter
10) type in exit and press enter
and you're done.