HD4890 - ERROR: clGetPlatformIDs() -1001

Am trying to configure ocl 1.20 to run on an old PC equiped with an ATI HD4890.

Keep getting "ERROR: clGetPlatformIDs() -1001" with the Ati-suggested driver. The required 14.4 simply won't install.

Any ideas on how to make it happen? (older ocl version / drivers?)

Thanks