sandisk error

I removed my sandisk that had data on it to use the USB drive for my printer.  When I re-inserted it. I received a message to format the disk.  I am afried to do that because I have important data on it.  I have tried to remove it and re insert it. but get the same message.  How should I proceed?

In a Command Prompt window run a CHKDSK /F  x:  command for the drive.  Hopefully that will resolve your problem.  And in the future use the Windows’s Safely Remove option to remove USB drives.

I did use window safe remove option.  Thanks for the repy.  I will follow your directions and cross my fingers.