Windows 7 doesn't boot up anymore

I've recently installed Windows 10 technical preview on a different HDD and that worked. And then i decided to switch back to my usual OS windows 7, and it tells me this: "Reboot and Select proper Boot device or Insert Boot Media in selected Boot device and press a key"

 

(This is when i select P2: ST500DM002-1BD142 in the BIOS. Reference the attachment)

 

And if i select a different HDD (not the one that has windows 7 or 10 installed, rather a secondary storage space), it boots up into Recovery mode and tells me that my PC/Device needs to be repaired. 

Error code: 0xc000000e

 

(This is when i select P0: ST500DM002-1BD142 in the BIOS. Reference the attachment)

 

and then it gives me the options to 

Press Enter to try again (Pressing this just flashes my screen)

Press F8 for Startup Setting (This one also just flashes my screen)

Press F9 to use a different operating system (This one takes me into several different options, these can be seen in the attachments)

 

Then, it gives me the option to 

 

Startup Repair (Tells me i have no errors)

System Restore (I dont have a backup)

System Image Recovery (I dont have a recovery)

Windows Memory Diagnostics (I dont have problems with my RAM)

Command Prompt (Well, i dont know how to use command prompt unless i have a tutorial)

 

Please Help!!!!! 

 Ummm...idk how to add attachments. help me with that too :P

You should have options in the bootloader for W10 and W7. If this isn't the case, you need to fix the boot menu. You can do it with a recovery disk or USB. You can make one if you don't have one. There are a lot of tutorials on youtube for both.

 

boot into windows 10. install easybcd and add your windows install to the bootloader through that and see if it works.

 

it should have a list popup that you need to select on everyboot now or after 30secs it will load the default one.

 

 

you dont need a recovery disk, you can do it with any windows install disk.

 

you just have to press shift +f10 i think it is to get cmd to open (i cant remember the exact combination but a google search brings it up)

True. I was assuming that it was an OEM install. Not sure why now.