This guide works for Windows XP, Windows Vista, and Windows 7.
To format your USB flash drive / flash memory card
1st Plug in the USB
2nd open up 'My Computer' which can be found in the start menu
3rd Right click the removable disk drive that you want to format
Note -Formatting a USB flash drive deletes ALL existing data, so it suggested to back up any data you want to keep.
4. Click "format" on the menu
5. A new window should appear named 'Format Removable Disk" should appear
6. Make sure 'Quick Format' is NOT selected, make sure the 'File System' is set to 'FAT32', the 'Allocation unit size' should be set to 'Default allocation size' Then Press 'Start'
7. A new window will appear informing you that this will erase all data on this disk, be sure that you have any data you want to keep backed up already. Then press 'OK' to continue.
8. The process may take some time depending on how large the USB is, once complete you will have successfully formated a usb flash drive / flash memory card.
Hope This Helps!