Updating Windows 10, after first reboot, I receive "Missing Operating System"

Not sure exactly what point the Win10 installer got to on my Asus laptop running Win7 Home Premium, but had precisely the same result. Black screen, "Missing Operating System'' and no idea what the next step should be here.

I have an Asus also

I have exactly same problem when upgrading to Windows 10 (from 7 SP1) on my Lenovo T410.

After copying files reached 100% installer performed a reset. Then computer displayed Missing operating system.

When I connected disk to additional PC I saw that Win10 installer damaged system partition - it was not readable (looked like not formatted one), while other partitions on same disk were ok.

Luckily I did a whole partition backup before installing Win 10, so I was able to recover Win 7 to the state just before Win 10 upgrade.

I powered down the desktop, waited a few minutes, then I powered on the desktop, the setup completed successfully, and all my files were intact.  My disk drive had no errors as well.  

Same problem going to try downloading the stand alone iso and see if it can repair 

Update: Delete all partitions on drive (Including any oem or recovery partitions), formatted new partition and disable EFI in Bios. Clean installed windows 7 and the win 10 upgrade worked.

Sad news to report... Took my Asus to the Microsoft store Answer Desk. Lots of poking and prodding and shaking of heads....and finally, 0KB on the C: drive. They're now doing a clean install, but data and applications are gone and won't be back until I reinstall.

Lesson learned to (1) not trust Microsoft's automated installer and (2) to back up more regularly. Luckily, this computer didn't have critical files, but......

Pretty frustrated that an installer would work this way...

bootrec.exe /FixMbr and

bootrec.exe /FixBoot didn't solve the problem for me.

I had same situation with free space - it looked like I had 0KB free on C: drive (before the upgrade I had 80GB free on this partition.).

Hi all,

I had the same problem, too. Also with a Notebook from Asus.

My System:

Asus Notebook K53SV
Intel Core i5-2410M
6,00 GB RAM
Windows 7 Home Premium 64Bit
nvidia Geforce GT540M

I tried installing the upgrade via the "normal" update from windows itself and a second time via media creation tool. Both times I got the "missing operating system" error.The download folder that contained the windows 10 data was only 2,7GB. Isn't that quite small?

I have an Asus desktop gaming system.   Have attempted twice to install Win 10.  1st time, got to 100%, rebooted and went to blank screen.   Contacted Microsoft Help Desk (7 times all total with over 2 hrs. wait time each time).   Got the computer Reset (wiped all personal files/programs) and installed Win 8.1 again.  2nd time got to 10%, rebooted and blank screen.  I have since reinstalled Win 8.1 again.   My wife has had very good luck using HP Win 10 install service ...one laptop and one desktop all up and functioning fine.  

08/05/2015.   just wanted to report that on the 3rd try, my system got Win 10 installed completely.  Everything appears to be working fine.   Only difference that I can tell from my previous two attempts was 1) I used the Control Panel/System and Security/Check Updates to install ALL updates prior to Win 10 install ...INCLUDING the actual Win 10 update install; I did not use the Get Windows App to update and 2) I installed my Nvidia drivers PRIOR to starting the Win 10 update.  

So far the only "bug" I am running into is as I have only a single monitor, my mouse keeps going "off screen".