Illegal characters in path
 

I am trying to encrypt a web.config file using the following command i am getting the error like below:

"Illegal characters in path"

aspnet_regiis.exe -pef "connection
Strings" "D:\Password Encryption\DPAPITestWeb\DPAPITestWeb\" prov "DataProtection
ConfigurationProvider"

web.config section has been provided below :

could encrypt this in different machine. But only this issue arrises on my machine.