Blinking black screen?

[MrTralala]

Hi guys. To start off, some things to note about my computer:

 

- It is Windows 7 64 Bit

- For quite a while now, it has this weird stutter sometimes where my computer freezes for a few seconds and resumes again. Usually happens when I am         playing games or watching videos

- I have not had the problem I am about to state before, it is my first time. I did not download anything for the past few days as well. Shouldn't be virus related, I hope

- This problem was suddenly temporary fixed, and thus I am able to post a discussion here

- I actually had changed my graphics card from a GT630 to a GTX750 Ti, ever since then my start up screen had to be different, it said "American Megatrends" when it starts due to problems with how it was manufactured. I wasn't the one who fixed it though, it was my sister's friend.

             

Computer Specs:

 

Motherboard: Acer Predator G3620

Processor: Intel Core i5-3470 @3.20 GHz

Graphics Card: Windforce GTX 750 Ti

Ram: 8GB

 

So basically my computer was very cranky today. It was in the afternoon when I came home to on my computer but to my surprise, it was stuck at the start up and had a black screen with the blinking '_' like so:

 

 

I asked my sister for help, and she said to actually remove and put in the two ram sticks back into the motherboard (she took this from the internet). Ok, so I did that and the problem was still there. After that, I removed my 32GB Thumbdrive and internet adapter and poof, it suddenly managed to boot up. You might think that is the problem, but why does that happen? Is it really something to do with my plugged in drives?

 

Thanks in advance~

 

Little about myself: I actually 14 years old haha, but computer hardware and all piques my interest, so I decided to learn more about it through Linus' videos. But they're still a lot of fundamentals I don't understand though. I hope to build my computer one day though, if that's possible. Another thing, I actually dk how to display my computer specs that are important, would be great if you could teach me.

[Eniqmatic]

 

snip

 

Check your boot device order, it probably restarted then was trying to put to the USB stick. Make sure your HDD is set to the first boot device in the BIOS.

[MrTralala]

Check your boot device order, it probably restarted then was trying to put to the USB stick. Make sure your HDD is set to the first boot device in the BIOS.

How do you set the HDD to be the first boot device in the BIOS?

[Eniqmatic]

How do you set the HDD to be the first boot device in the BIOS?

Go into the BIOS and look for boot order or boot priority or something similar. If your stuck post pictures of what your BIOS looks like.