My PC does not boot when I change settings in Bios

I have converted recently my C: drive from mbr to GPT and boot using UEFI Windows 10 1909. I adjusted the bios settings to use UEFI and the PC boot normally. Today when I opened my PC, a blue screen appear with information that it does not recognise my boot files or somthing similar so I remember that I changed PCI settings in Bios from "Auto" to "Gen3" when I entered the bios and changed back my PC returned to boot again !!

Why this happean and how to change the Bios settings without lost boot my PC normally ?

I would have a look and see if the available PCI-E slot bandwidth is supported by both your graphics card and version of driver you are running.

Some graphics cards today running v2.0 are still lighting fast. If a particular card isnt backwards compatible with certain BIOS settings, it may well throw up a blue screen.

Both links I would just leave on Auto for now. Maybe do a benchmark test with some popular software and see how your system stacks up against other folks running similar hardware, then you'll know whether its really worth it or not

Thanks I have GTX 1060 card but on AMD motherboard B450. So since the card is PCI 3 and the motherboard support Gen 3 I tried to set it to gen3 but it give me the blue screen if it was not on auto !! I feel that it is a motherboard Bios bug.

Okies well there is possibly other BIOS settings in conjunction with the Gen settings.

Have a look, see if you have any other DMI or ASPM generation settings, that only have Enabled or Disabled. Like there might be other individual Gen 2 and 3 settings that require disabling.

The default BIOS setup would cater for all gen cards and always boot. Whereas you are wanting Gen 3 all the way. So have a good mooch through all the Advanced System configs including the onboard CPU graphics if there are any. Disable all onboard support to stop other possible conflicts.

Peace

Thanks

Yes the motherboard has another PCI-E set it to disabled ? What is DMI and ASPM ?
No onboard GPU.

Yes you try and set it to disabled.
The other settings are to do with power management. Like idle time and reducing current For now it could be a good idea to disable all power management settings as they will only cause interference with your test.
Links speeds keep on auto whilst you slowly disable everything power magagement wise. Its like disabling intel speed step for the cpu but for the graphics slot instead.
Trial and error with consistant reboots and observation will see you right.

ok thanks the problem is my motherboard MSI B450 Carbon Ac is very hard to enter the bios. I have to press on delete for many times and also press on reset and restart several times to enter the bios. It is a new motherboard and I am not happy that I got MSI.

Right ok sorry to hear that bud. We'll sort this out easy enough though

First thing i would do is turn the machine off and disconnect all your external USB's and any extra Card readers connected to the motheroard seperately, keeping keyboard obviously. Then disconnect all hard drives and pull the Ethernet cable out of the machine as well.

Pop the battery out of the Motherboard for 30 seconds, if you can. Sometimes this is easier than accessing any jumper. My board has a special cmos button i can press to reset, which makes it easy.
So once battery back in, try and proper fresh BIOS start and see how you get on after that.

ok thanks, I also read that if I change boot settings with UEFI enabled I have to reinstall Windows ?

Hehe that was going to be my first question.
From what you said i want sure if you had changed the setting after install or not.
Well yes for sure you have to do a fresh install after changing.
Im surprised it even boots if you have changed to GPT and still on original Legacy install

Yep, fresh install. Remove any 2nd hard drives whilst you start fresh