Access to Homegroup blocked - Windows blames NIS

Since Windows 10 hosed my laptop, I had to wipe the hard drive to get rid of it and reinstall Windows 7 Professional. My desktop is running Windows Home Premium. Both are fully up to date, with the exception of KN 3035583. Word of caution: Do NOT install this update. It loads the auto upgrade to Win10 app.

Anyway, I cannot access the shared files and drives in my homegroup now. Both machines are running NIS 22.5.2.24. I got the homegroup password off the desktop and entered it into the laptop join homegroup box. After several minutes a message says the join failed and to run the troubleshooter. The troubleshooter says I should get rid rid of NIS and use Windows Firewall instead in order to join the homegroup. Yeah, like that's really going to happen, relying on windows firewall.

I can see all the shared directories and discs on the desktop from the laptop and vice versa. If I try to access one, I get the message I don't have authority. I've set the shares to full access. What else can be done?