HELP! Major issue with Dell Latitude E6540 with Radeon 8790m

[TeslaK20]

Specs:
Intel i7 Haswell Processor
Radeon 8790m GPU
16 GB RAM
1TB SSD
Windows 8.1 Enterprise

When attempting to connect the computer to a triple monitor setup' it would only connect to two at a time. I figured this was because there were no drivers for the Radeon GPU, and the PC was instead working off the integrated Intel 4600 graphics. While installing Radeon drivers downloaded from Dell, the screen started flashing wildly, the computer would not respond, and the pointer was stuck on a loading wheel. After forcing shut the computer and turning it on again, the flashing persisted, this time in a bootup splashcreen. I have tried several times to turn it on and off again. I have sometimes gotten to the login screen, but after that it always crashes.

Can anyone help me, please?

 

[m&m's]

Enter the BIOS and disable the 8790M, tells it to use the 4600, save & reboot, uninstall the AMD/Dell drivers, enter the BIOS again, enable the 8790M and download this http://support.amd.com/en-us/download/auto-detect-tool.

 

[TeslaK20]

Thanks. Unfortunately, while I can enter BIOS, I have extremely limited experience using it. Could you outline the steps of disabling the GPU?

 

[m&m's]

Your BIOS probably wont look like this one and might be completely different, but you get the idea. This video might not be relevant, you have to search by yourself in the BIOS and it's possible that there's no options to disable it. If it's flickering during the splash screen (before any drivers are loaded), you should RMA it, the laptop is defective.

 

[red_stapler]

The E6540 doesn't have the option to disable hybrid graphics. Also, the Intel 4600 supports 3 monitor setups.

Are you getting the flashing after disconnecting monitors? Does the flashing occur outside of the OS?

 

[TeslaK20]

Yes and No

 

[TeslaK20]

Your BIOS probably wont look like this one and might be completely different, but you get the idea. This video might not be relevant, you have to search by yourself in the BIOS and it's possible that there's no options to disable it. If it's flickering during the splash screen (before any drivers are loaded), you should RMA it, the laptop is defective.

Not on the splash screen, but after it. Right when Windows loads.

 

[red_stapler]

So it's doing it right as the driver loads. I'd say it's time to uninstall both video drivers, run ccleaner/driver sweeper, and then reinstall.