I would back up everything and format.  Better to have a backup and spend the time doing so than losing all your data.

(08/03/2011 06:32 AM)Takeda Wrote:  so, there is a program to let my delete this? or i have to format it? but I'm afraid to format it because i don't want to broke my memstick, or who knows if the bad sectors will increase from 1.37 GB to more.

Formatting shouldn't break your memory stick, and increasing the number of bad sectors would be a "good" thing, since it means that you're less likely to corrupt.