Botched dual boot attempt - HELP!

So here is the skinny:
Computer in question already had working win 10 on it. Was running separate machine with XP on it for recording but machine died so I have to use win 10 machine. Have dual booted computers before so seemed like no big deal. Now win XP is installed but 10 is not able to start. Edited boot.ini and added 10 but was getting hal.dll error. Changed partition number and then got ntoskrnl.dll error. Used XP disk (don't have 10 on a DVD or flashdisk yet) to try and fix issue. Botched both OS's, MBR is bad (BootMGR missing or corrupt - Ctrl, Alt, Del)). Reinstalling XP at the moment but want to fix the boot. I Have 10 install and recovery partition on drive. Can put it on a stick once XP is reloaded. What to do after that?

Download and Run Easy BCD and Add the Windows 10 to the Boot loader.

The problem is that you need to add Windows XP to the Windows 10 boot loader. It sounds like you were trying to add Windows 10 to the XP boot loader which will not work.

Lets say you have a HDD running Windows 10 installed. You add a Windows XP HDD. Continue to boot into Windows 10 (it sounds like you booted into Windows XP instead). The Windows XP partition will get a drive letter in Windows 10, let's say E:\. Then in Command Prompt (Admin) in Windows 10 you run:

BDCBOOT E:\Windows /d /addlast

That adds the Windows XP on drive E:\ to the Windows 10 boot loader. As long as the Windows XP partition containing the operating system is intact, that's all you have to do. You don't need the XP boot loader files.

Thanks for the replies. Will use program mentioned above to fix. Sounds like it should work. Ya know I used to be all over this kind of stuff...now I just want the machines to work.
Thanks again.

Uhh, The problem I'm having is I can't get into win 10, so is there a way to do this from XP or am I SOL on the 10 install?

Why can't you get into Windows 10? What error are you getting?

Only XP comes up. If I try to add win 10 to the boot order within XP I get the above mentioned errors after I select win 10. I've got to fix the win 10 boot sector somehow from outside of win 10. Is there a way to do this?

Oh and btw, I cannot access the repair/install files as XP does not recognize the space those files reside in and I don't want to alter the location by assigning a drive letter to it as it might damage it.

LHoCA said:

Only XP comes up. If I try to add win 10 to the boot order within XP I get the above mentioned errors after I select win 10. I've got to fix the win 10 boot sector somehow from outside of win 10. Is there a way to do this?

Make a USB or DVD/CD of Kyhi's Recovery Drive. Boot into that, run Macrium Reflect. Under the restore menu is an option to fix Windows boot problems.

Windows 10 Recovery Tools - Bootable Rescue Disk - Windows 10 Forums

Used the boot iso to get into a really cool fix-it environment there. Used Macrium, followed the cues. Got both OS's working now!
You da Man!

Glad it worked for you!