Sorry to hear about the issue you are facing.
1) Have you applied a latest patch of Win10-2004 after which you are facing this issue ?
2) Could you confirm me the current version of Acrobat Reader DC that you have ?
3) Could you please do Help → Repair Installation and see if it fixes the issue ?
An error occurred while saving the commentMichael C. Nesel commented
OK, fixed it. Here's how I did it.
1) Uninstalled AR DC using Windows uninstall app
2) Ran Adobe Cleanup for Reader
3) Restarted PC
4) Ran CCleaner
5) Ran CCleaner on registry
6) Ran MS Disk Cleanup on C: drive, including System Files
7) Restarted PC
8) Downloaded current Adobe Reader DC Version 2020.012.20048 from Adobe
- Unchecked Chrome extension, unchecked both McAfee options, run install
9) Downloading OK, Installation Complete
- uncheck "Launch" box, click Finish
10) Set Adobe Reader DC as default for PDF files
11) Everything looks OK, no lockup - Version 2020.012.20048 now showing in "About"
12) Restarted PC
13) Everything still looks and behaves OK