Thanks for the feedback. Would it possible for you to share the installation logs from your W2K12 server machines? The logs are generated in the %temp% folder. The Unified installer log will be named like: AMDUnifiedSDKSetupMSI_amd64.log.
Well, today the situation seems to be different (I wonder if it's Monday...) - the unified installer does not start installing any more i.e. after "preparing to install" it reports "This installation package could not be opened. Verify that the package exists".. etc pp. Probably I only tested this installer on the W7 machines. Does the log that is generated by the regular installer help?