Partition Won't Boot After Resize

Sorry to ask a question right away, though I suspect that most people join to find an answer/solution to a problem.
I have a 1 TB HDD with 4 partitions, all windows and all bootable. Till now. I have had 2 win 7 partitions and 2 win 10
partitions. The one win 10 partition was my main, and default. The one win 7 partition was my main win 7 partition,
although I didn't use it a lot. The other win 10 partition was mostly for youtube, etc., and trying out programs to see
if I wanted them on my main. The other win 7 partition was mostly empty, used mostly for trying drivers, as drivers
for win 7 can be difficult. My main (win 10) partition started to give warnings about low disk space, so I decided to
delete the one, barely used, win 7 partition and use the now unallocated space to my main win 10 partition, for a
temporary solution to my lack of space on my main.I used MiniTool for both operations, performing each one separately.
I used the MiniTool on a different partition, since I have it on all partitions. I use it a lot, and have never had any problems.
So now my main, default win 10 will not boot; the 2 remaining partitions boot just fine. I find this to be a problem that
shouldn't even exist, and seemingly have a simple solution. It hasn't proven to be so.
I know people will ask: Dell Latitude E6530, Seagate HDD. Thank you in advance !!

 

Well, maybe it's not MiniTool. But, it's likely something with the UEFI bootloader, or perhaps how the partition is marked? Perhaps it's set as non-bootable?