HD 4850 Detection Driver Failure

i have a HD 4850. i have it working right now but id like to upgrade the
drivers but when i try to install its keeps saying:

----------------------------------------------------------
Existing packagesCatalyst Control Center
ATI Catalyst Install Manager
ATI Display Driver
Microsoft Visual C++ 2005 Redistributable


Other detected devices

Error messages
Failed to load detection driver
------------------------------------------------------------

im not shure what else to do. i just cant figure it out. any help would be
greatly apreceated. thanks in advance

Alice