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Old 02. May 2015, 07:26 AM   #3 (permalink)
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Location: New Zealand
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Originally Posted by foxygrandma View Post
Laptop is TOSHIBA Satellite C55-A PSCF6U-01Y00C

Am on Windows 8.1

Any time I restart and my usbs are pluggd in, after the Toshiba logo comes on, I get - operating system not found, try disconnecting any drives that don’t contain an operating system. Press any key to restart- and when I press Enter it goes to the desktop. If my usbs are not plugged in ,I do not get the message.

Strange that the computer repair where I took it for another problem about two months ago and this problem started said they did not know how to fix it. I am 80 years old and need detailed instructions. Thank you. Anna Ruth
Your problem is likely to be because a technician has changed the boot mode from UEFI to CSM (Compatibility Support Module) which allows booting from legacy (old-style) MBR (Master Boot Record) drives because it looks at the boot sector on a drive and ignores the partition table that UEFI uses. This is done so someone can boot from a different drive with their operating system and run their own diagnostics and software on your computer without changing the software and settings that are already stored on your computer's drive.

If you change the boot mode back to UEFI then your computer will not try to boot from USB because that feature is not supported unless you are in CSM mode.

This Toshiba support webpage shows what was done and you just have to reverse it by resetting it back to normal:
1. Power on the system and while the "TOSHIBA" logo appears, press [F2] key to enter the BIOS Setup Menu.
2. Select [Security] tab and set the “Secure Boot” to “Enabled”.
3. Select [Advanced] tab and go to “System Configuration”. (Refer to <Pic.2>)
4. Set the “Boot Mode” to “UEFI Boot”. (Refer to <Pic.3>)
5. Press [F10] key to save and exit.

Hope this is detailed enough for you ... and that it works for you. I don't have a Toshiba laptop to test in on.
Better to light a candle ... than to curse the darkness.

Last edited by Remah; 02. May 2015 at 07:28 AM. Reason: Spelling
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