There are many Windows 10 users reporting that Windows Updates are getting stuck at various % points. My brother had this problem on his pc and tried various methods to solve the problem but only the below instructions worked. Hope it works for you too.
1. First right-click on the Start Menu button and select Command Prompt (Admin)
2. Type the following command and press Enter:
net stop WuAuServ
3. Right-click on the Start Menu button and select RUN type %windir% and press Enter:
Then in Windows folder, find SoftwareDistribution folder, and rename it to SDold
4. And open again a Command Prompt with Admin, and enter or copy-paste the following command:
net start WuAuServ
After that try to check for updates again.
Hope this helps.