To start...
For this you will need some form of recovery media, which means you'll need to use another Windows 7 PC to create it. Follow the instructions at SevenForums to do that.
The repair
Rebuild the BCD. Boot into the recovery media, and select Command Prompt. Type
bootrec /rebuildbcd
and hit enter.
Reboot
If the above didn't fix the error, you may have to set your Windows partition to Active. Reboot back into the recovery media, and from the command line, type
diskpart
select disk 1
list part
You'll then have to determine which partition should be your active partition, and then set it to active:
select partition x
active
quit
Replace X with the correct partition number.
Reboot
If that still hasn't fixed the issue, you'll have to restore the MBR. This is a bit more complex.
Reboot back into the recovery disk, and select command prompt.
Now we're going to have to determine the drive letter your recovery disk is on:
diskpart
select disk 0
list volume
Search for the item that has CD-ROM in the Type column and make note of the value in the LTR column - this is the drive letter.
exit
Simply type the drive letter like so, and hit enter:
D:
Then type:
cd boot
dir
You should see a bootsect.exe file listed. If you don't: STOP, go and get a Windows Installation Disk and try again. Otherwise...
Type
bootsect /nt60 SYS /mbr
and hit Enter.
Once you see Bootcode was successfully updated on all targeted volumes, type exit and then reboot your computer.
Hopefully then your issue will be fixed.
Please note you follow these instructions at your own risk, and I assume you have a basic knowledge of Command Prompt. If you're unsure, please ask a professional.
Best Answer
All the errors you are getting relate to a mismatch between the BIOS/UEFI and the Windows version that you are trying to install.
You have probably changed some settings in the BIOS/UEFI that make it incapable of installing neither 32-bit nor 64-bit Windows.
To install Windows to an EFI-based computer, you must enable EFI mode in the computer’s firmware and boot with 64-bit media.
If you don't know what you changed in the BIOS/UEFI, I suggest to reset it to default values, then examine it well in order to see whether it is UEFI or BIOS, and if UEFI then ensure it is really set to boot in UEFI mode.