Import-module fail

I am using Windows 7, dont know why cannot import-module,

Previously, I can import-module, like grouppolicy and etc.

but now i will get the error

PS C:\Users\xxx>Get-Module -ListAvailable
Get-Module : Cannot find drive. A drive with the name 'd' does not exist

PS C:\Users\xxx> Import-Module grouppolicy
Import-Module : Cannot find drive. A drive with the name 'd' does not exist.

Any ideas? I think some path set wrong, but dont know where should I set. Thanks