Recently, I accidentally clicked a rogue program that infected my Windows system with a virus. All executable files, including cmd, were unable to run. Here is the fix.
Right-click on the desktop, create a new txt document, and add the following content:
assoc.exe=exefile
ftype exefile="%%1"%%*
Then change the file extension from txt to bat, and double-click to execute it.
Attachment https://www.cnop.net/uploadfile/2020/0507/20200507091710574.zip