Maxtor Ext Hard Drive Delay-Write Error

I put an attachment in here, hopefully it will be visible. At times when using the on button to turn on my Maxtor Ext hard drive & add a folder then turn it off using same button I get a write error msg telling me that that the file could not be saved. I do not understand this. Am I not opening or closing down the hard drive properly. According to the attachment, which I can bring up by rt-clicking on the hard drive tray icon to safely remove hardware. There are options in here to choose from. Will using any of these options be the better way to close it down & which do I choose?

 

Well you should just select the top line (Maxtor.....) and then click on stop aaand then wait for the message to tell you it is ok to remove the drive.