Erasing an RW CD

How do I erase an RW CD? I went to disk utility and tried to click on the erase button but it is greyed out. What should I do?

Not enough information. Which Mac do you have - year and model? Version of OS X?

Assuming your optical drive is OK, you might want to use a better program than Disk Utility. Download the free "Burn" from Sourceforge and use it to erase a CDRW disk.

Hi, new member here. Switched to Mac about a year ago, but still struggle with things every now & then. SO, I have searched all over and found this thread, hoping it had my answer, but no...??

On El Capitan, I have an external USB DVD rewriter, which works great. However, after I burn an ISO on a rewritable cd, I can't later erase it. (it's a Kaspersky/Linux rescue boot disk to be used on other PCs) As soon as the ISO disk goes back into the burner, it's not recognized by OS X and so it doesn't show up in Finder, and although it does show up in Disk Utility, all options, except info, are greyed out.

I assume there's got to be a way to erase (non-native?) RW CD using El Capitan, but I can't find it.

Details: OS X ver 10.11.3, Mac Mini late 2012, Samsung SE-208 USB DVD re-writer.

Thanks, Randy

Welcome to the forum, Randy. Are you saying that you can burn a CD-RW disk on your Mac, but then when you reinsert it a second time it cannot be read? And this is all happening on the same Mac? What are you using to burn the CD? IOS is a Windows format for disk images, so I'm a bit confused on what you are trying to accomplish.

I assume there's got to be a way to erase (non-native?) RW CD using El Capitan, but I can't find it.

Click to expand...

First... as inexpensive as CDs and DVDs are, why are you using RWs? Re-writable media are unreliable and should not be used. Second, did you read my reply above about downloading "Burn" and using it to erase the CDRW?

Hi Jake,

Yes the disk is created, and needs to be erased on, the very same Mac.

The disk I created was a bootable rescue CD, which boots to a flavor of Linux. I used OS X to burn it... which couldn't be easier. From memory, I downloaded the ISO, right clicked on it in finder, then chose burn. However, later when I placed the same disk back into the very same burner attached to my Mac, a pop-up says "the disc you inserted is not readable by this computer." Since drive/disk doesn't show up in Fiinder I figure Disk Utility must be the answer. But no, the only available option there is Info. All other options are greyed out. My google searches on this turned up nothing useable. So I figured it's time to hit the forums.

Thanks, Randy

Hi chsag,

I do tech work occasionally out of my house, and in this case, I needed to download an updated tool to boot a Windows PC from CD in order to scan for any nasties. Once that was done, I simply wanted to erase the CD-RW and place it back into the storage bin.

The reasons I use rewritable media for these types of tools: I only needed this for a one time use; if I were to use a NON-rewritable CD, it would be *outdated by the next time I needed to use it... say in a few months; I rarely have problems with re-writables.. but yes over the years, I have tossed a few RW discs which would not verify. Probably more of those than regular CDs.

*I used Kaspersky in this case bc they constantly update their Rescue ISO, so there's no need to do a definitions update after booting the PC... nice!

Yes, I just downloaded "Burn" and it did the trick, Thanks!

--I figured OS X could do this alone.. but with me being a n00b and all, I didn't know the 'simple' command line instruction needed to mount the disk??

Thanks again, Randy