Bootcamp disapear after update to El Capitan

ELC has System Integrity Protection enabled. Please see Boot Camp disappeared after El Capitan update as a reference on how to get Gdisk working.

ELC has System Integrity Protection enabled by default. To disable it temporarily for diagnostics purposes, (this is the correct version of the nvram command you referenced earlier).

a. Boot into Local Recovery. Power down your Mac, power it back up, and hold the Command+R.

b. Run Utilities -> Terminal

c. Type csrutil disable

d. Exit Terminal

e. Reboot normally.

After the reboot, install Gdisk.

Please choose /dev/rdisk0.

Install GPT Fdisk (aka gdisk). Leave your Testdisk display and start a new Terminal Window. You need to use the following steps. If you see any error messages during the following steps, please stop and post back here with the error message. The following steps have values from your Testdisk output (and you can verify) in Steps 7 and 8. Please notice the'+' sign in step 8 (this is called offset notation). The text in parentheses is for informational purpose to describe the action being taken. Gdisk has one-character commands except when entering numbers.

Rebuild GPT4 using start/end offsets

1. Sudo gdisk /dev/rdisk0
2. P (print the full list of parts)
3. D (delete)
4. 4 (part 4)
5. N (new part)
6. 4 (part 4)
7. 779728896 ( - Start offset in sectors or the start point for Bootcamp part)
8. +197044224 ( - Size offset, as opposed to End offset)
9. 0700 (Windows part type)
10. P (print list of all parts just to see what changes will be made)
11. W (Write the new GPT)
12. Y (Yes! really write the new GPT)

This will delete and re-write the GPT partition info for /dev/disk0s4.

Rebuild MBR to match the new GPT information thus resetting the Hybrid MBR. Use defaults for other questions (like partition codes). The only values that need modifications are the Boot flags and step 10. Accept all other defaults that Gdisk offers. Please see thesample Q&A as an example. These steps can be repeated if you make a mistake before you get to Step 12, otherwise start from Step 1 for these steps. Step 6 has numbers which are typed with a space between the numbers. Please see the sample Q&A before you execute these steps.

1. Sudo gdisk /dev/rdisk0
2. P (Print list of parts)
3. R (Recover)
4. O (print current Hybrid MBR)
5. H (chooses Hybrid)
6. Partitions numbers to be hybridized: 2 3 4
7. Y (Good for GRUB question)
8. N (part 2 boot flag)
9. N (part 3 boot flag)
10. Y (part 4 boot flag make NTFS bootable partition)
11. O (print current Hybrid MBR)
12. W (Write the new MBR)
13. Y (Yes! write the new MBR)
14. Reboot

Here is sample Q&A for this section. Please notice the Press Enter/Return.

Place EFI GPT (0xEE) partition first in MBR (good for GRUB)? (Y/N): Y

Creating entry for GPT partition #2 (MBR partition #2)

Enter an MBR hex code (default AF): Press Enter/Return

Set the bootable flag? (Y/N): N

Creating entry for GPT partition #3 (MBR partition #3)

Enter an MBR hex code (default AB): Press Enter/Return

Set the bootable flag? (Y/N): N

Creating entry for GPT partition #4 (MBR partition #4)

Enter an MBR hex code (default 07): Press Enter/Return

Set the bootable flag? (Y/N): Y

Test 1 - Does Bootcamp Volume show up in Finder?

Test 2 - Can you see files in Bootcamp Volume?

Test 3 - Can you select Bootcamp in System Preferences -> Startup Disk?

Test 4 - If Test 3 is successful, select Bootcamp and Click Restart.

Run BC Assistant, use W8.1 ISO (if you no longer have it, you can download it from https://www.microsoft.com/en-us/software-download/home ), and use the 'Create USB Installer option'. Once you have the installer, you can boot from it and repair the windows installation. Please ensure the 'Remove Windows' is unchecked. On newer Macs, you may see only the Restore Option, which should not be used, otherwise it will wipe Windows.

Tj3n wrote:

Thank you so much for your help >_< i though can repair my windows partition without needing to redownload everything, but i guess i have to then i will just use my win 10 iso that im having to reinstall new bootcamp, so in the BC Assistant i will choose the Remove win.... to make it 1 partition again right?

You should be able to fix the current installation and then upgrade to W10 without having to re-install Windows. The upgrade will register your Mac with Microsoft, which allows you to re-install a clean copy of W10 on the same hardware as many times as you need. It will give you some experience with the W10 process.

Anyway may i ask is it possible that Win 10 auto update can break Bootcamp? 😐 on older BC i can safely disable the update, but not in 10

Yes. Driver updates cause the most problems. The BC6 drivers update is now available under Windows 10 Update. It is new but should be capable of handling such conflicts better than it has done one in the past.

You should create a W8.1 backup before you upgrade to Windows 10.