Q: "Missing Operating system_ " After installing Yosemite

The Testdisk scanning does take up memory, but you do not have any memory pressure. If you have important data, and have a restorable backup, nuke-and-pave takes less time.

I have been in the same boat and this has been quite helpful

thank the two of you!

However I think at this time it is best for me to just delete the partition and say bye to Bootcamp windows.

I will have to retrieve some files from PC but most have been on google drive.

Hope it works for you Lokomix!

1. Are you running test disk with sudo?

2. It may be able to read the log you created so quit, restart Testdisk, and then use Append, rather than create. I have never tried to go back to a Deeper Search. If it does start anew, you can always click on Stop, but you somehow need to find your files.

3. Nuke is always an option.

Do not remove Windows via Disk Utility, because it will cause you grief. BA cleans up both the GPT and MBR when restoring the disk to a single partition, so it should be used. You should be able to install W7, but if you had a 32-bit which was done on an older version of OSX, newer version of OSX may only support a  64-bit version, so be careful.

If you recall I pointed out that you had missing 30+ GB (500 - (419+40)). The BA delete shows 459, so you have less contiguous space than you can re-arrange partitions on.

The only method is to start an Internet Recovery (Command+Opt+R and get the spinning globe), erase your internal disk, restore from a Time Machine backup and then re-install Windows via BA.

Yosemite is a nightmare for Bootcamp users.

If you have a 2012 rMBP, it should support Internet Recovery (Command+Opt+R when rebooting the Mac). If you do not see a spinning globe, it is not internet recovery. You should use a wired connection, not a wireless connection. Wireless connection will be too slow.

Yes, but anticipate problems. See some posts at the end of Can't format former Boot Camp partition.