Greetings VQT, what brand Mother Board OR what make and model of PC do you have and I'll look it up for you.
@domoore thank you that would be quite neighborly of you!
I have a Lenovo A520 All-In-One (AIO) circa 2013.
Greetings VQT, wow, I read through the maintenance manual, I'll attach a link for you, one for the pdf manual, and one for Lenovo's support page.
Even to pull out the battery looks like a lot of work with this one, the manual says to use a function key to reset the BIOS, but what you need to know is how to reset it when it won't go to POST (the same problem I had). I have read several people that simply unplug the Lenovo and let it sit for 30+ minutes and then try again. I'm not sure if that will help. I would suggest calling their (Lenovo's) technical support line on Monday if that doesn't work. They should be able to walk you through a solution. a LOT of people are having this happen to them. I honestly wish I could be of more help to you, this is the most frustrating thing I've had happen after ANY software "update." Microsoft knew about this problem three months ago, yet they haven't fixt anything, seriously, they should be footing the bill to have these PCs fixed. Good Luck, seriously I hope you get it going, DM
https://support.lenovo.com/us/en/troubleshoot/LPT000542?firstpdt=LPT000422
https://download.lenovo.com/consumer/desktop\_pub/ideacentre\_a520\_hmm-fru\_20130419.pdf