Dell 1558 Primary Laptop Screen Not Booting; But External Monitor Works

[Yaj8552]

So this is actually the first time I've ever joined a forum so hopefully I do this right! Question's kinda wonky too. (Basic specs at the bottom)

So I don't know why but my computer keeps booting on my external monitor (attached through VGA) rather than my primary laptop monitor. It's not just windows but the BIOS screen too.

Here's the thing, my driver is the standard VGA driver (rather than the ATI Radeon Mobility 5470 driver) that comes with windows 7 so I can't go into catalyst control or, after it boots up, just go to "Screen Resolution" and switch screens since the laptop screen isn't even detected.

Why I have the Standard VGA driver is because most likely my GPU is physically broken due to there constantly being vertical lines on my primary (when it was working) and external monitor even with the Standard VGA driver and even during the boot screen. When I try to update the driver my computer ALWAYS get the BSOD from the apikmpag.sys file. When I took a screen shot and emailed it to myself it was a normal line-less picture so not software related.
I'm generally pretty decent with technology, I'm no novice at the very least. And I've looked on multiple forums and spent weeks doing different things to solve this problem. But I've come to the conclusion it's probably broken and I should replace the motherboard or just get a new computer.

However, I can live with polarized images and lines across the screen and a terrible terrible resolution for a couple weeks/months until I get the money for a new computer. But I would like to use my primary screen on my laptop so I can at least keep my laptop mobile. I almost always had my external screen plugged in and until 3 days ago my primary screen was working then my computer just decided to boot using the external screen.

So is there any way to boot up my computer to my primary screen with the Standard VGA driver rather than my external monitor? I think it has to be a setting in BIOS that I'm just not finding. Or should I just assume it's a problem with my broken GPU even though the external monitor is working?

Sorry for the long question. If you have advice for my apikmpag.sys crash I'd be happy to hear it. But my primary problem is the primary monitor not booting so please try to answer that issue.

Again sorry for the length and thank you in advance! =)

spec:
Dell 1558 Laptop (around 4 years old)
Windows 7 64 bit
Intel i7 Q720 1.60 GHz
8 Gb RAM
ATI Radeon Mobility HD 5470
Standard VGA Driver
BIOS A12
Idk if any more are even important

 

[jpishgar]

Attaching a tutorial that might be instructive.

Also, for that BSOD, check out the answer here:
http/www.tomshardware.com/answers/id-1656824/atikmdag-sys-error-bsod-startup.html

 

[Yaj8552]

I can barely count how many times I tried doing the BSOD fix you posted. Probably a couple dozen times with different files and different versions of the driver. Thank you for the reply though! I really do appreciate the effort!

And for the display tutorial I got stuck at step two since pushing windows+p did nothing except make my cursor into the loading cursor for 2 seconds. I tried doing that like 20 times with restarts and failed driver updates.

I think either my broken GPU fried the screen. Or fried the connection to the screen. What I might do now is go to a computer repair store and see if I can attach the LVDS and inverter wires to some other motherboard and see if it turns on. Good idea?