Computer keeps rebooting

[Astralogic]

Hi, I turned on my PC todaay (I dual boot Ubuntu and Windows 10), and booted into Windows and everything was going really slow until after a few mins the PC blue screened and turned off.

After turning it back on everything was going slow even at the post screen, it would take a while to display and it would appear on the screen slowly from top to bottom the same as the boot menu.

If I try to boot into an OS the computer shuts down and if I try to boot from the ubuntu installation USB the same happens.

My specs are: Windows 10 x64, 16gb ram, MSI GD65-Gaming motherboard, GTX 1080

Any help appreciated

Edit: The computer boots into the insstallation USB if I don't use UEFI mode.

Edit 2. More details: When I first turned my PC on I booted into Ubuntu and was on it for about an hour, everything was fine. The slowness/shutdown issue only started once I booted into windows.

Edit 3: So I booted into the ubuntu usb and ran the repair tool (even the boot options seemed fine). This solved the slow bootup and now Windows boots up (havent tried ubuntu yet but I assume it will work). The problem is windows is now running slow for no apparent reason.

 

[Space_Ranger]

I'd check the event viewer and look for System Errors.

 

[Astralogic]

I think my H100 may not be working correctly and my CPU is overheating. Is there a way to test if the H100 is still pumping? The fans are working.

 

[Astralogic]

Looks like my pump died CPU temps are soaring. Gonna buy a new cooler.

 

[Space_Ranger]

Looks like my pump died CPU temps are soaring. Gonna buy a new cooler.

Thankfully that's not all that expensive to replace..

 

[KarsusTG]

Looks like my pump died CPU temps are soaring. Gonna buy a new cooler.

That sucks op. Coolers are easily replaced though so at least there is that.

 

[B00nie]

Get a treadmill and install a pump on its axle. You get exercise while you cool your computer.