Частичный ответ
Это копия и вставка с форума поддержки HP по этому вопросу:
Was your video card built by AMD/ATI? If so, the Vari-Bright feature must be on. To fix this go to: 1. AMD Vision Engine Control Center (or AMD Catalyst Control Center) 2. Power 3. PowerPlay 4. Uncheck the "Enable Vari-Bright" option. and that will fix your problem.