Can't use Bootcamp because of partitions. Need HELP

Can you show a screen shot of Disk Utility with your Mac partition selected? Also, open Terminal and type diskutil list and post the results here.

Ok, you have a CoreStorage volume for your OS X install which, at times, makes it difficult to delete/merge partitions into it.

So, there may be a way to recover that 16mb and let you use Bootcamp again. But, remember to always use the Bootcamp Assistant to remove your Bootcamp partition. Never use Disk Utility to do so. I'm not saying you did anything wrong. Just something to remember. Normally, the Bootcamp partition is AFTER the OS X partition.

Open Terminal and type diskutil cs list. Towards the bottom of the output should be a line that says Revertible: and to the right of that it should tell you whether your CoreStorage volume is revertible or not. Let me know or post the output from the command.

Great!

So, now do a full system back up. After that, you can open Terminal and type diskutil cs list again. Above the Revertible line should be a line that says Disk:. You want the value to the right of that line. For example, it may say disk1. Now, you can revert your CoreStorage volume by typing diskutil cs revert <value from Disk: line>. For example, diskutil cs revert disk1. This should revert your file system back to the native file type. This command is a non-destructive command so you shouldn't lose anything. But the back up is just in case. From there, open Disk Utility and see if you can deal with that small 16mb partition. Or post screen shots here.

What does diskutil list show now? Does it still show your 16mb partition as the 1st partition? I remember DU shows it under your Macintosh HD.

You might have to back up your system, boot from an external source into a Recovery HD using the OS X Disk Assistant and a USB thumb drive; then use Disk Utility to repartition your internal drive into one. Then you can either Reinstall OS X and during the Setup, migrate your user account, settings, data and apps or Restore Your System from your Time Machine back up.

Actually, your best solution is to re-download OS X El Capitan from the App Store / Purchases tab then create a USB installer thumb drive (8GB) using this link.

Then you can use the above to boot from, fix your internal drive and re-install OS X all from that USB thumb drive. Then during Setup, use Migration to migrate everything over from your Time Machine back up. I assume you use TM to do your system back ups.

With Disk Utility, you can only merge downwards. Because your 16mb Untitled partition is the top one, you have to delete everything below it then merge the freespace into Untitled. It's better to delete all partitions and repartition into 1 partition. This way you start clean with one partition. Just make sure to back up your entire system with Time Machine.

NOTE: El Capitan will probably recreate that CoreStorage volume during install. That's what it's designed to do with some laptops. This isn't a problem and you can always revert it back like you already know how to do.

Restart using the USB thumb drive installer.

Go into Disk Utility and select the drive not any of the partitions. Click the Partitions button in the toolbar.

Select the Untitled partition and change the Format to OS X Extended (Journaled). Click the '-' sign then Apply.

Select the Mac partition (larger one) and click the '-' sign. Make sure the Format is OS X Extended (Journaled). Click Apply. The format needs to be the same for all your partitions to let them merge. The Mac partition should merge with the Untitled after you delete/format it. And your blue pie chart should be all blue with the label of Untitled.

With this newer Disk Utility, it's difficult to use. I'm still learning and experimenting. When things go wrong for me, I use Terminal and clean up the disk that way with diskutil commands. Needless to say, I'm not fond of this newer GUI Disk Utility.

If the above reply doesn't work, try deleting all partitions so you have free space. Then ADD a single partition as Format: OS X Extended (Journaled) with the GUID Partition Scheme.