Ionic instalation issue

I am trying to install ionic.

I had set up node.js, Java SDK. and ionic via node.js

When i am tryg to run ionic from cmd ı have got some error.

>     C:\Users\aaa>ionic info
>     module.js:472
>         throw err;
>         ^
>     
>     Error: Cannot find module 'C:\Users\aaa\AppData\Roaming\npm\de_modules\ionic\bin\ionic'
>         at Function.Module._resolveFilename (module.js:470:15)
>         at Function.Module._load (module.js:418:25)
>         at Module.runMain (module.js:605:10)
>         at run (bootstrap_node.js:423:7)
>         at startup (bootstrap_node.js:147:9)
>         at bootstrap_node.js:538:3
>     
>     C:\Users\aaa>

Why ı am getting this messages ?

I have try to re install several time. but the result have same.

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