I solved this problem in accordance with the figure as mentioned below:
run in cmd
npm install -g @angular/cli
Afterwhich:-
Open in Windows 10) Control Panel\All Control Panel Items\System or accordance with the figure
Step 1:
![enter image description here](https://lh4.googleusercontent.com/e5-s7ICKbfNP6S7sE6z5cOjlilNLGR9w-Em_jJnmEDfyv747VGNPjzpMqIZ2x4BbsuYLBB76RSTYfhbEP-RaDBxo1jClHqABN1m_HA5AqZjPAm5p4OYJprHh2HDFo5ux_rhMghVZ)
step 2 :
![enter image description here](https://lh4.googleusercontent.com/4yWduouEt6XMs1nfULJgzBBCny6mNuyhVeEdgErk397y4OUv6aQYw2uc0DRV0qgOBI8lwcX404K4mxedN-sGs6V9S1LC-CCbFBuh2IganbrAGqI6qxu5OATAou4xU1aI8JYSp9bb)
Step3:
![enter image description here](https://lh6.googleusercontent.com/ST_mC3P2QL3T8e-zkZly87xk2TupnFwGj_9lZerG_ixoUHCyPQeqO4Q3w0T-iXCHyktI1YT5wn0jTFEsP84X_8aSscsrJjcDGYUB3psH8Y3Gv2lkArslyNhTlPo0ETrvHFoW84hA)
Step4:
![enter image description here](https://lh5.googleusercontent.com/o8Zk2o9d69FKtsFKEULc4GZcjbr_RJwGWQMo9yf4NlFGq2_XCacN9HDv2CV3skqesyFPq5FcmZeiOB-5dWmFmGRnF7FvIiGgE6v-wZ2WlYp0A-Mhje0SsX9J4gkdOQQne5TyVmbi)
Step 5: Include the missing ng path
![enter image description here](https://lh3.googleusercontent.com/YfCXJOJ5D6h5g1m_BP53G-YZ9qz9RCqaGStRlAgFW_PvvMIfSDErropKjotCyQ-uI0I9GNAxkmTJ1GnxsVhoVTTIK5Wrwwq0wKilrSzW7HEHSlPIeLYfemMdc3_-zfBuQ5TBA_hy)
Mentioned below is a new environment variable that you need add:
C:\Users\PK\AppData\Roaming\npm\node_modules\@angular\cli\bin
To conclude, please restart all opened command prompts and try again.