Ok, Danke für die hilfe, bin jedoch eindeutig zu der Erkenntniss gelangt.
Win XP prof SP3
12-6_xp32_dd_ccc.exe
AMD-APP-SDK-v2.7-Windows-32.exe
Funktioniert nicht!Please note that AMD Crossfire™, OpenCL, and AMD Eyefinity are not supported by the AMD Radeon HD 7900, AMD Radeon HD 7800 and AMD Radeon HD 7700 Series GPUs on Windows XP. New technologies introduced with the new AMD Radeon HD 7900, HD 7800 and HD 7700 Series are incompatible with the Windows XP (released 2001) operating system, and are designed to work on current operating systems. AMD CrossFire technology, OpenCL and AMD Eyefintiy are supported under Windows Vista® and Windows 7 for the AMD Radeon HD 7900, HD 7800 and HD 7700 Series GPUs.
http://support.amd.com/us/kbarticles/Pages/hd7900seriesxpsupport.aspx https://bitcointalk.org/index.php?topic=86547.msg1068668#msg1068668Danke!