npm start error

[prabhavatiwaghmare]

[email protected] start C:\Users\SAI\Desktop\reactproj\my-app
react-scripts start

'"node"' is not recognized as an internal or external command,
operable program or batch file.
npm ERR! code ELIFECYCLE
npm ERR! errno 9009
npm ERR! [email protected] start: react-scripts start
npm ERR! Exit status 9009
npm ERR!
npm ERR! Failed at the [email protected] start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR! C:\Users\SAI\AppData\Roaming\npm-cache_logs\2020-10-30T12_34_55_994Z-debug.log

show this error for npm start command
node v15.0.1
npm 6.14.8

please explain and help to sol this error

thank you