the error on all mailboxes and all CAS servers , its suddenly happened 

also  when i try to open the power shell directory from the Exchange Back end site from IIS I received access denied , them I added the Organization management group on the security permissions , then its opened 

currently when I opened the authentication of the power shell received the below 

• Edited by Mahmoud Adel Ibrahim 23 hours 43 minutes ago

Hi.

For me it looks like your system drive has been reassigned for a new letter (from D: to C:).

Are you confirming this?

Hi

no its the same 

C: system drive

D: Exchange Data Program file

Hi 

i have a problem when open Exchange power shell I receive < The WinRM client sent a request to an HTTP server and got a response saying the requested HTTP URL was not available >

this error is in all exchange servers <mailbox and CAS>