Sorry to hear about your W10 no-access issue.
Depending on what you answer back to kemical, he will have some suggestions for you I'm sure.
Generally speaking though, if those suggestions don't product a positive result I would consider doing a couple of things to get your 6 mos. of stuff back. Any programs you installed on W10 are gone; you can't get those back.
However, all or most of your personal data such as library folders, E-mails, etc. can be gotten back from data recovery.
I suggest you use an Image Backup program such as Macrium Reflect and backup your existing W7 partitions and save them to an external drive. Next, find or buy yourself another hard drive, preferably new of similar or higher capacity than the drive you have in your computer now. Remove the original drive from your case, and install the new drive into the case. Using the Rescue Media (DVD/CD or USB stick) you make prior to creating your Macrium backup image to external media, boot your computer up and perform a Restore Image of only the W7 partitions onto the new drive. This will give you an operating "clone" of what you have now less the W10 stuff.
Once you've done this, I suggest you take that original hard drive into your local Computer shop and pay them to do a data recovery for you, specifically all the data from your W10 system partition and burn onto DVD media or an external hard drive. From there, you can then decide whether to re-attempt your W10 upgrade from W7 on your new replacement drive or simply upgrade your system Mobo as kemical suggested or even build an entire new W10 system from scratch.
In either case, if you do get onto W10 on your old hardware or your new build, you'd now have all your W10 personal data to copy over to that new drive on the W10 build. You'd get everything back data-wise, but you'd still have to reinstall all your old W10 programs manually from original disc media, usb media, or Internet download.
I'd also mention that if the Techs you pay to recover your W10 data cannot do so, that power loss event may have permanently damaged your original hard drive and that drive would need to be sent out for very very expensive data recovery. I just did one for my son's external hard drive that cost me about $550. I was able to get about a 97% data recovery percentage, which is excellent, but there are only 2 places in the country (US) where they do that kind of a job on a dead or failed drive. Post back and I can provide that for you if you like. Hopefully, you get a resolution before you get down this far in my post to the dreaded last resort pro data recovery.
Best of luck,
<<<BIGBEARJEDI>>>