Formerly, I was able to move my files into my flash disk. But later on, I wasn't. Why? I have also scanned it with scandisk and already performed error-checking (no bad sectors). Should I perform disk defragmenter?

Hello, misterbean: Do you get an error message when you try to copy to the flash drive? What is the make and model of your flash drive? Do you have anything on your flash drive now? Does your flash drive have a write protect tab? This is on a Windows 98 or ME computer, right?