I brought a brand new pc at last week. It worked fine but sometime it was hanging/freezing with a sound and there was no control from keyboard & mouse. So, I have to direct shut down my pc by restart button of my cpu. For this reason, I reinstalled windows. One thing I can add that at the time of installing windows there was error. It told that windows couldn't installed on MBR disk, so I had to format my hard disk and converted that MBR to GPT by cmd. Anyway, after installing successfully I saw that there is an watermark though windows is genuine!
Well, I think the full watermark is coming for this reason, "SecureBoot isn't configured correctly". So, I searched solution for this SecureBoot and tried to enable it via BIOS. But, changing that option was disable at there.
Anyway, the main reason for re-installing windows was solving freezing issue. But, after installing windows again, still freezing issue exist with no keyboard/mouse control. Only difference is no ugly sound this time.
Another thing I noticed that POST screen isn't coming at the time of starting windows. So, I can't go to BIOS normally by pressing Del button or other options(like boot screen by pressing F12 button). If I unplug my cpu's plug from main line and then plug-in again, only then Post screen has come and I can go to BIOS. But, after that if I restart my pc or open my pc at another time, Post screen won't come again! I mean, it only comes after unplugging cpu's plug and re-plugging each time!
So, summary of my problem:
1. PC is freezing sometime and keyboard/mouse don't work that time.
2. SecureBoot option is not configured correctly.
3. POST screen is not coming so I can't go to BIOS screen and boot screen normally. It comes only after re-plugging CPU with main line each time.
I have already installed updated drivers and re-installed windows. Still those problems happened. So, I am very frustrated now. How can I solve those problems?
PC Configuration:
1. Intel Processor Core i7 3.6 GHZ 4th GEN
2. GigabyteB85 Chipset Motherboard GA-B85M-D3H
3. Graphics Card MSI R7 260X 2GBD5 OCV3
4. Gaming RAM G-Skill Tridentx 16GB (8*2) DDR3 1600 BUS CL10 1.65V
5. Gaming Power Supply Corsair VS450
This is my first post at here. Please, consider if I make any mistake at here. Thanks in advance.

Well, I think the full watermark is coming for this reason, "SecureBoot isn't configured correctly". So, I searched solution for this SecureBoot and tried to enable it via BIOS. But, changing that option was disable at there.

Anyway, the main reason for re-installing windows was solving freezing issue. But, after installing windows again, still freezing issue exist with no keyboard/mouse control. Only difference is no ugly sound this time.
Another thing I noticed that POST screen isn't coming at the time of starting windows. So, I can't go to BIOS normally by pressing Del button or other options(like boot screen by pressing F12 button). If I unplug my cpu's plug from main line and then plug-in again, only then Post screen has come and I can go to BIOS. But, after that if I restart my pc or open my pc at another time, Post screen won't come again! I mean, it only comes after unplugging cpu's plug and re-plugging each time!
So, summary of my problem:
1. PC is freezing sometime and keyboard/mouse don't work that time.
2. SecureBoot option is not configured correctly.
3. POST screen is not coming so I can't go to BIOS screen and boot screen normally. It comes only after re-plugging CPU with main line each time.
I have already installed updated drivers and re-installed windows. Still those problems happened. So, I am very frustrated now. How can I solve those problems?
PC Configuration:
1. Intel Processor Core i7 3.6 GHZ 4th GEN
2. GigabyteB85 Chipset Motherboard GA-B85M-D3H
3. Graphics Card MSI R7 260X 2GBD5 OCV3
4. Gaming RAM G-Skill Tridentx 16GB (8*2) DDR3 1600 BUS CL10 1.65V
5. Gaming Power Supply Corsair VS450
This is my first post at here. Please, consider if I make any mistake at here. Thanks in advance.