SafeHandles For Compact Framework

I have some code that is working fine in my desktop application. I would like to do the same thing in windows mobile application (Motorola MC9090), but I get error:
"Type 'Microsoft.Win32.SafeHandles.SafeFileHandle' is not defined."
I tried to add Namespace: Microsoft.Win32.SafeHandles but then it says:
"Namespace or type specified in the Imports 'Microsoft.Win32.SafeHandles' doesn't contain any public member or cannot be found. Make sure the namespace or the type is defined and contains at least one public member. Make sure the imported element name doesn't use any aliases."
and the problem remains.
I tried to add every possible reference but there's still no SafeHandles...
Please help...