It seems you did not run an elevated command prompt (with administrator privileges). You are supposed to run Command Prompt with elevated privileges (permissions) to be able to access the BCD store. This has been simplified in Windows 10, you simply right-click the Start menu button and select Command Prompt (Admin). This is what is referred to as an elevated Command Prompt, remember that next time you come across such terms in given instructions.
Straight up, should I format both partitions and reinstall both would this be the best way to go?? Yes I remember vista first lol.
If you do not mind starting over then go ahead. I advise you manually create the necessary partitions for both OS beforehand instead of shrinking the Vista partition afterwards. Use DiskPart (ran from Command Prompt) as follows:
1. Detach ALL storage devices (including external ones) except the SSD. You want the SSD to be the only storage device attached to the computer at the time of running DiskPart and creating partitions. This is to minimize the very real risk of partitioning the wrong disk and losing data. If your motherboard has SATA 6Gb/s ports, connect the SSD to such a port for optimum performance. The ports are often numbered from 0, ie SATA 0, SATA 1 etc. You want the SSD on the very first port (SATA 0).
2. Power on the PC and boot from the Vista installation media. When the language selection screen appears, press
Shift and
F10 to launch Command Prompt. Run the following command-lines (in blue capital letters), one at a time and in their order of listing as follows (the lines below the command-lines are just notes for your attention and NOT commands to be run)
DISKPART
Launches DiskPart (disk partitioning utility)
LIST DISK
This isn't necessary if you detached ALL storage devices except the SSD, but it's good to confirm that the SSD is in fact disk # 0 and it's the only one listed. It's also a check to see if the SSD is detected/present.
SELECT DISK 0
Selects the SSD (first disk) for the DiskPart operations that follow.
CLEAN
Erases all partitions from the disk selected above. This is a risky operation and can lead to data loss if done on the wrong disk, the more reason why the SSD needs to be the only storage device attached to the PC at this point. I cannot emphasize this enough, so take your time and follow instructions precisely.
CREATE PARTITION PRIMARY SIZE=350MB
This is the System Reserved partition and its 100MB in Vista by default, but 350MB in size by default in Windows 10. Since you will be installing Windows 10 as well, I recommend we use the Windows 10 default size. 100MB may cause problems if Windows 10 finds it to be insufficient in space and needs to update its contents.
ACTIVE
Sets the newly created partition as the active (boot) partition.
FORMAT FS=NTFS QUICK LABEL="System Reserved"
Formats the new partition and assigns the label.
CREATE PARTITION PRIMARY SIZE=80920MB
The above command creates a second partition that's 80GB in size (80 x 1024), since 1GB = 1024MB. You can allocate a smaller or larger partition size as desired. I would however advice to allocate the largest space to the Windows 10 partition and keep the Vista partition smaller, but this is purely a matter of personal preference. I assume Windows 10 will be your main OS.
FORMAT FS=NTFS QUICK LABEL="Vista"
Format the newly created partition for Vista. The label is optional, but I recommend assigning it to help easily identify the partitions.
CREATE PARTITION PRIMARY
Creates the third and last partition for Windows 10. We omit specifying the size so that it is created using the remaining unallocated space.
FORMAT FS=NTFS QUICK LABEL="Windows 10"
Again, the label is optional.
EXIT
Quits DiskPart and returns to Command Prompt
EXIT
Exit Command Prompt and return to the language selection screen. Proceed with Windows Vista setup as usual. When you reach the partition selection screen, you should see the three partitions that we just created. Select the Vista partition and proceed with setup until Vista is completely installed. The labels should make it a lot easier to select the target partiton where to install Vista and Windows 10.
After installation of Windows 10 is complete, you should now be getting a boot menu from which you can choose the OS to load. Report back if you encounter any errors or negative results.