Happy New Year to everyone..... I recently bought a WD elements to back up my machine. I have no idea what I must have done wrong. I plugged it in and when it came up, 'do you want to use "elements" to back up with time machine' ,I clicked on 'decide later' because I was not expecting the word 'elements' to come up and didn't want to hit something wrong. So I google some info, during which I had also 'ejected' my external hard drive. When I plug it back in, this option does not come up. So I look into 'system preferences' and click on time machine. It comes up saying, 'in order to start backing up with time machine, the disk 'elements' must be erased. Erasing will destroy all information on the disk and cannot be undone." The options below are 'erase' or 'choose another volume' I have added 2 screenshots of this. first one is what I wrote above. the second one is the contents of disk. I am SO CONFUSED as to what to do. I am STILL a novice when it comes to the technical aspects of computers, and always worry about erasing something that is vital to my computer's performance or just running in general. Could someone please please assist me regarding this, in 'hold my hand' and 'step by step' suggestions????? Also, once this is figured out, will I be able to just delete most of the stuff on my computer? I am thinking that I have something that may be slowing it down. I also have LOTS of photos and music. I would like to keep the music so I have instant access all of the time, but guessing that if I do, in fact, delete the pics, maybe it would help?? I just have noticed it lagging a bit and don't know enough to know what I can & can't erase from the machine. For example....caches and history. Is it recommended to clear the history and clean/clear the caches every so often? I have never done either and have had it for a couple of years. I have the Unibody OS X Version 10.5.8 with 2 GHz Intel Core 2 Duo Processor and 2GB 1067 MHz DDR3 I really appreciate everyone's help, many of you have taught me lots. Thanks!! I hope everyone has had a great holiday season full of love & happiness. I hope the new year brings you all peace!!!