Here’s what I’d do:

https://www.dell.com/support/home/en-us/drivers/driversdetails?driverid=30n00&oscode=wt64a&productcode=alienware-13-r2

Then I’d put that on a USB and then click F12 when restarting the laptop and enter the bios flashing utility.

Never use the windows method unless you know what your doing and are not restarting the computer.

Thanks for the tip but I am unable to enter BIOS flashing utility. I tried F12, F10 and F2. But no luck

When I switch on the laptop all the rgb and Fans run but there is no display.

Did you try using the Dell BIOS Recovery Tool?

https://www.dell.com/support/article/en-us/sln300716/how-to-recover-the-bios-on-a-dell-computer-or-tablet?lang=en

You can also try resetting the NVRAM manually by removing the adapter, battery and both memory sticks (and CMOS battery if it's easy to get to) and doing a power drain by holding the power button down for 30 seconds. 

If this doesn't work then you can try another technique that has been proven to work on some machines. Fingers crossed it may work for you.

1. Turn the system off and disconnect the AC adapter
2. Disconnect CMOS battery and system battery** (some people have noted that removing the CMOS may not be required)
3. Do a power drain (press and hold power button 30 seconds)
4. Remove all memory modules
5. Reconnect AC adapter and power system on
6. Let laptop beep until it turns itself off
7. VERY QUICKLY, WHILE IT IS OFF, BUT BEFORE IT ATTEMPTS TO BOOT AND LIGHTS COME ON AGAIN, INSERT 1 MEMORY MODULE
8. System will start to beep 5 times
9. Power system off
10. Reconnect CMOS battery and system battery

What’s that little piece of metal under the ram slots @mattyb3?

The one called CLRP1.

What picture are you looking at? Not sure what you mean. 

Hi, I couldn't remove the CMOS as its hard to reach it but I followed all the steps but still stuck on blank screen.

One thing which is not aligning is in step-6 my AW keeps beeping infinitely with 2 beep interval instead of 5 beeps and than stopping. So I had to switch it off using power botton. Can you tell if I did something wrong. Thanks

I've looked it up. Yeah that looks like a very helpful feature. It only says that the 13 R2, 15 R2 and 17 R3 have it though. 

Good for this guy as an extra chance of saving his system though

The little metal thing on the ram slot area that says CLRP1?

People say if the computer can’t start anymore then they press that one with a metal tool on both sides of the metal pin and then it turns the computer back on again?

I've actually never seen or heard of it. Sounds like a good thing if they added it to later models. I don't think any of my machines have it but I've never looked. It's never come up on any threads I've read before. 

It sounds a lot like what the older desktop motherboards had where they used a jumper pin to reset the BIOS

I tried to find the CLRP1 but I couldn't locate it but instead My AW 13 is having CMOS1. Not sure if it is the same. Attached image for your reference.