XPS 15 9550 NO BOOTABLE DEVICES Windows 10

I have been having problems with my XPS 15 which original came with a 1tb hdd and a 32gb ssd. I recently replaced the hard drive with a 2.5 inch sata ssd and removed the on board m.2 and installed Windows to it and it was giving me frequent blue screens and drive was not being detected until I restarted until one day it would boot.

If I understand correctly, you currently have just the 2.5 inch SATA SSD in your system.  You installed Windows to that while the SATA controller was set to AHCI.  Did you do a clean install of Windows or use an image for the original configuration?  That should have worked as long as you are not trying to reconfigure the Cache drive using the Intel Utility.

Whenever you change the SATA controller type, make sure and use the msconfig.exe procedure to set the system to boot back into SAFE mode after you change it.  If you need help with that, let us know.

If it works normally in RAID mode then it looks like you need to leave it there.  That mode basically sets the M.2 slot to run as SATA so they could set up the pre-cache drive (32 GB) to use the Intel Utility to accelerate the HDD.

If you get a chance, take a picture of your Disk Management window using the snipping tool and attach while in Rich Text mode for your reply.  I normally limit the size of the media to 250-300 since the default 550 can get very large.

Thanks for taking the time to reply. I currently cannot boot into windows which is the main issue I am trying to solve.

I did use disk imaging software to preserve a previous installation of windows. And it worked fine for a while until it started giving me blue screens

No boot drives are listed in the bios when I am in ahci mode.

When I switch over to raid the efi is listed but When I try and boot to the partition it shows me a black screen with small white text.

I cannot access the operating system to make changes to msconfig

The image was taken on a system installed without RAID enabled or the 32gb ssd installed

When I try to boot to windows boot manager using f12 it shows a black screen for a while and then a black screen with white text:

Press F1 to retry reboot

Press F2 to reboot into setup

Press F5 to run on board diagnostics

When you boot to a UEFI system you have to boot to the Windows Boot Manager.  You should be able to see that option on the F12 Boot Device Menu during boot.  

It sounds like the correct boot device is not showing up in AHCI but does in RAID?  If that is the case, I would boot as RAID.  If it boots that way, leave it there or change to AHCI by starting while in Windows.

USB drives should not be effected by the SATA setting.  They should show up in the F12 menu just as a normal Windows Boot Manager entry.

Since the system was giving Blue Screens after using the Imaging utility, there may be some basic problem with that configuration.  That image was taken when the system was running with the 32 GB drive being involved?  If you don't know how to turn off the acceleration in the Intel utility, let us know.  

If you want, you can download the Win 10 install media and do a clean install, if only for testing.