PC sometimes fully shuts down and Immediately reboots

[OhaiItsBrad]

Occasionally when turning of my computer, the fans will shut down, and everything will go as it should, but about a second later, the whole system starts back up again. I can confirm that I am not hitting restart as A: I have looked to make sure I am clicking shut down and B: When I do click restart, the fans continue to run as if the system was on.
Is it possible the relates to other inconvenience I have where peripherals (mainly the mouse) will light up when clicked and remain for a few seconds, but only after the computer has been shut down, and unplugging it fixes the problem.

Specs incase this matters
- Windows 10 64 bit
- CPU: Intel Pentium G3260
- Gigabyte H81M-S2H (Not sure on BIOS version)
- 2x2Gb Nanya RAM (DDR3, Not sure on speed)
- EVGA Geforce GTX 660 superclocked
- WD Black 500Gb Boot drive and mass storage
- Samsung SSD 120gb (Not sure on the exact specifications of this such as the series it is, but I highly doubt this is the problem. (This is not my boot drive as it was installed at a later date, and I do not know how to transfer my operating system over)
- FSP group Hexa+ 500W PSU
- FSP P2000 computer case (I'm putting this here because I have a slight suspicion this might be the cause)

Anything that could help would be greatly appreciated. Thanks. 

[DeltaGames]

If you do not click the mouse after hitting "shut down", will the computer turn off correctly? Have you tried different mice? Also, for instructions on transferring your operating system, click here for a post that will help you.

[DrMacintosh]

5 minutes ago, DeltaGames said:

 Also, for instructions on transferring your operating system, click here for a post that will help you.

Would highly recommend against transferring the OS. Things could easily go wrong and then you can end up with a lot more headache than if you just fresh installed Windows. 

[DeltaGames]

1 minute ago, DrMacintosh said:

Would highly recommend against transferring the OS. Things could easily go wrong and then you can end up with a lot more headache than if you just fresh installed Windows. 

If you read the post, the tool just copies the disk, so, if it does not work, no data will be lost.

[TAHIRMIA]

6 minutes ago, DeltaGames said:

If you read the post, the tool just copies the disk, so, if it does not work, no data will be lost.

That's basically cloning the disk and any windows problems will just move over along with it. 

OP would just need to copy important information to another drive and do a clean install of windows

[OhaiItsBrad]

5 hours ago, DeltaGames said:

If you do not click the mouse after hitting "shut down", will the computer turn off correctly? 

Now that I think about it, I think hitting the mouse any time during the shutdown period may trigger it. I'll try later. 

[iLenovo]

21 hours ago, OhaiItsBrad said:

Occasionally when turning of my computer, the fans will shut down, and everything will go as it should, but about a second later, the whole system starts back up again. I can confirm that I am not hitting restart as A: I have looked to make sure I am clicking shut down and B: When I do click restart, the fans continue to run as if the system was on.
Is it possible the relates to other inconvenience I have where peripherals (mainly the mouse) will light up when clicked and remain for a few seconds, but only after the computer has been shut down, and unplugging it fixes the problem.

Specs incase this matters
- Windows 10 64 bit
- CPU: Intel Pentium G3260
- Gigabyte H81M-S2H (Not sure on BIOS version)
- 2x2Gb Nanya RAM (DDR3, Not sure on speed)
- EVGA Geforce GTX 660 superclocked
- WD Black 500Gb Boot drive and mass storage
- Samsung SSD 120gb (Not sure on the exact specifications of this such as the series it is, but I highly doubt this is the problem. (This is not my boot drive as it was installed at a later date, and I do not know how to transfer my operating system over)
- FSP group Hexa+ 500W PSU
- FSP P2000 computer case (I'm putting this here because I have a slight suspicion this might be the cause)

Anything that could help would be greatly appreciated. Thanks. 

Just blame Windows 10 forced updates.