[SOLVED] Need some help with "An operating system wasn't found"

[MaikelAt]

Hello!

I know this might be a famous issue but I can't get to solve it...

First of all: how did this happen?

My PC was working just fine before a friend of mine asked to upgrade his Motherboard (Prime x470 Pro) because he had bought a Ryzen 3600 and he could not use his build without his mobo upgraded.

He came over and I turned off my PC. I disconnected the psu power cable. I pulled out my CPU, Mobo and GPU power cable. my RX580 was next to be pulled out and right after that my stock cooler. Next the CPU.

CPU, Cooler and GPU was installed back in my friend's build. Next we installed all power cables and turned it on. Everything fine. Mobo upgraded successfully. He was running out of time so he had to leave. My thermal paste was a bit old and his 3600 came with a Deepcool thermal paste. He gave it to me and I cleaned everything from the CPU and Cooler, then I applied the paste with the "x" mode. He helped me installing the stock cooling and then he left. I installed everything back to my build and now I get the message:

"An operating system wasn't found. Try disconnecting any drives that don't contain an operating system"

When I got this message my keyboard was working fine. After getting this screen 2 times, my pc just stopped recognizing it. I installed my keyboard into my laptop and it is certainly working fine.

I need some help to fix this. All my files are in there and I can't get it to boot up.

My build:

Rx580 xfx
Ryzen 1200
Stock cooler
GIGABYTE AB350N (no WiFi)
1x8GB Fury Hyper X

 

[COLGeek]

This happens when the computer can't find a suitable boot device. Make sure that both your data and power connectors are firmly attached to all SATA devices.

After doing that, make sure your BIOS can identify all connected storage devices and that the intended boot device is selected as the default boot device.

 

[MaikelAt]

This happens when the computer can't find a suitable boot device. Make sure that both your data and power connectors are firmly attached to all SATA devices.

After doing that, make sure your BIOS can identify all connected storage devices and that the intended boot device is selected as the default boot device.

But without my keyboard working I wouldn't even be able to enter the BIOS.

 

[COLGeek]

Power the system down manually (if powered on) and check all connections. Restart and see if you can access the BIOS, then.

 

[MaikelAt]

Power the system down manually (if powered on) and check all connections. Restart and see if you can access the BIOS, then.

Sorry for the lateness... I did check that my sata and power cables were firmly attached but nothing happened; same issue.

I restarted the BIOS (pulling out the battery) and after that the keyboard did work... I entered the BIOS did some changes, selected correct priority boot (my drives and my USB are recognized by the mobo. [I also tried to boot without the USB plugged in and nothing, btw]) and same issue!. After getting the error trying to boot my keyboard won't work again.

 

[TerryLaze]

You have to put all your drives back to the same sata port they were before so that your old setup knows where everything is.
Telling your bios to start from the windows drive only works if the windows drive also contains the boot info.

An alternative way to fixing this is to boot up with an windows installation media either usb or dvd and enter the repair tool to fix the boot problems manually.

https://www.digitalcitizen.life/command-prompt-fix-issues-your-boot-records